


A New Gang

by tsukithewolf



Series: Road Trip AU [4]
Category: Undertale (Video Game)
Genre: Ambiguous Gender Little Pup, Ambiguous gender Frisk, Asexual Sans, Frisk is a flirt, Includes Pictures!, Light Sans/Frisk, Nyublackneko's AU, Other, PTSD Sans, Romantic Sans/Frisk, Triggered, alternating povs, crossover fanfiction, undertale mob au - Freeform
Language: English
Status: Completed
Published: 2016-06-11
Updated: 2016-06-11
Packaged: 2018-07-14 08:31:14
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 23,978
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7162496
Author URL: https://archiveofourown.org/users/tsukithewolf/pseuds/tsukithewolf
Summary: <blockquote class="userstuff">
              <p>Frisk is once again sent to another universe and gets involved with crime.<br/>Meanwhile Sans has to take care of a younger, quieter Frisk who has their own problems.</p>
            </blockquote>





	A New Gang

**Author's Note:**

> Wow! When I said that I had wanted to write a story for [Nyublackneko's Mob AU](http://nyublackneko.tumblr.com/post/138921378037/ut-mob-post-list) (IF YOU HAVEN'T READ IT, PLEASE GO SEE THEM!), I didn't expect it to become such a large project! Not only has Nyu worked so much with me (THANK YOU SO MUCH), but they've also drawn PICTURES!! Any and all art in this story belongs to Nyu! I'm so happy and excited and this whole thing has been so much fun, omg. 
> 
> So I would like to thank Nyu again for putting up with me and my questions! It's been an honor and I can only hope I've really made the characters come alive and kept them in-character! Also a thank you to my beta joviamod as well! And to my friends who have read through my story and have encouraged me and everything! Thank you!
> 
> That all being said, let me get a couple of notes out of the way.  
> For those of you who have NOT read my "Dreams of the Past and Present" series, you're still good! You don't HAVE to, really. The only things you need to know (that you won't only discover in this story) :
> 
> -Frisk is 18-19 in this story, having matured over the course of my story.  
> -Sans and Frisk are ROMANTIC in my universe. This pops up a number of times, but there's no heavy stuff, so no worries!  
> -Frisk is a bit of a flirt.  
> -DotPP!Sans has PTSD from the events in the Underground. This will come up. This is your warning.
> 
> Also, this story jumps back and forth between universes.
> 
> That all being said, please enjoy!

It was a sudden pull to Frisk’s entire being that sent their mind spinning and their body to its knees. Somehow that feeling was familiar, but they couldn’t quite place from where. They didn’t think that it could be a terrible thing, though, because they could make out their surroundings despite the scrambled thoughts. They were in a . . . (they searched for the word) warehouse? It took a moment to even process that. There were wooden crates everywhere covering the grey floors and lining the equally grey walls. It smelled a bit musty.

Sans was standing nearby, which served to comfort Frisk quite a bit. Whatever had occurred, Sans had also come with them. What _had_ happened to them? They climbed to their feet slowly and held their head in their hands for a few long moments until their mind steadied. They looked up at Sans and opened their mouth to question him, but he beat them to it,

"hey there, pal." His voice had that false levity lacing through it that always set off warning bells in Frisk's head. "thanks for _popping_ by. always love strangers coming into my home. so. why don't you tell me how a human got here?" His grin widened, much more threatening than friendly.

Frisk’s immediate reaction was to wonder what they had done wrong, but that was before they realized that the skeleton in front of them was not Sans. Or, rather, that this Sans was not the same Sans that Frisk had grown up with. And judging by the tension in Sans’s jaw, this Sans was not happy to see them. Why had they switched universes again? This didn’t look like the place for a teleporter, or whatever.

“still dizzy? might be in your best interest to focus on me, buddy. wouldn’t want to have to hurt such a rare guest.” Sans was suddenly a lot closer, his presence seeming to loom despite the fact that Frisk was a bit taller than him. When had he moved? Was it a shortcut? But they couldn’t sense one. Were they just being that inattentive to the situation?

Considering the fact that they were backed against a crate, it probably _would_ be in their best interest to focus on the less-than-amused skeleton in front of them.

Frisk held up their hands in front of them non-threateningly. Sans’s smirked a bit. “nice of you to join us. kind of on a schedule here, and i’m afraid you’ve got some questions to answer.”

Frisk wondered how they would even begin to explain. They didn’t even have a clue of how they had ended up here. They were walking a tightrope. They didn’t understand why their appearance had pissed this Sans off, but they suspected that it probably had to do with the Frisk from this universe. At least _that_ Frisk would be safe from being threatened.

“I don’t know.” They finally told him, nervous but trying to hide it. Sans didn’t even have a weapon out (his hands were tucked casually into his dress pants. Actually, why was he dressed so nicely?) but Frisk still felt like there was a spear being held to their chest. And they certainly knew how that felt. “I’m not certain where I am.”

“or how you got here?” Sans questioned, finishing the cliche’d line. Frisk didn’t respond. Sans huffed an amused laugh, ducking his head some as he adjusted the straps of his vest. Frisk didn’t lower their hands yet. “how’d you get here, buddy?”

Frisk rolled various ways they could answer around in their head. They weren’t sure of this Sans’s story or how much he may know about science. They doubted bringing up alternate universes would be the wisest choice, but there probably wasn’t another solution. They recalled their father’s training and decided that calming the situation down would be best. They carefully lowered their hands, well-aware of Sans watching their every move. They let their arms hang. It was a sign of trust.

“I’m sorry for appearing.” Frisk attempted, “I understand that . . . your Frisk has disappeared, right?”

Sans’s gaze sharpened then. In a move too fast for the human to catch, Sans had a bone out and pointed at Frisk’s throat. Judging by the length and thickness, it was a male tibia. It wasn’t a sharp object, but Frisk knew better than to look down on the use of bones for fighting. They knew what kind of damage it could do personally.

Sans’s smile was serious now, the faux playful voice lost. “funny story. nobody should know that name. at least, nobody i care to be friendly with.” His sockets grew dark. “ **Where’s the kid**.”

Frisk swallowed and felt their throat roll against the end of the bone. So much for calming down the situation. Apparently they had grown rusty in their skills. Or maybe they had just grown rusty with dealing with a pissed off Sans. It had been a number of years since they had last seen him this angry. They could feel their limbs threatening to start shaking. Their heart raced. Now was not the time for old fears.

“I can explain.” Frisk said quietly, voice wavering just slightly. “But . . . you won’t believe me.”

“we’ll see about that.” Sans tapped the bone gently against the bottom of Frisk’s jaw, almost teasingly. Frisk lifted their head a bit higher, exposing their throat.

“No weapons. I’m unarmed.”

Sans considered the request for a long moment before he rolled the bone around his fingers and made it disappear. Frisk sighed silently and relaxed dropping their hands. The lights were at least back in the skeleton’s sockets, but they were still small.

Frisk still didn’t know how to explain this properly. They needed to talk quickly. “I’m Frisk too. But I’m . . . from a different universe.”

Sans lifted an eyebrow, disbelief subtly tightening the sockets some. Frisk was just thankful they could still read this Sans just as easily as theirs. They really didn’t want to have to Load a Save somehow. “universe?”

Frisk nodded. “Have you heard of parallel universes?”

“only from books.”

At least he had heard of them. “They’re real.”

Sans didn’t respond for a long moment before he grinned. “you’re right; i don’t believe you.”

“I told you.” Frisk whined, unable to help it.

“but let’s say you’re not lyin’ to me.” Sans shrugged. “you didn’t answer my question. where’s the kid?”

“In my universe. We . . . switched places.”

“and what is your ‘universe’ like?” His voice was bordering on dangerous again.

Frisk scrambled a bit mentally. “It’s safe. They’re with my Sans.”

“your sans.” Sans stated. Frisk nodded. Sans tucked his hands back into his pockets, staring at Frisk for a long time. Frisk didn’t talk, allowing him to think. They hadn’t been this scared of a Sans in a while. This was a very different Sans than the one they had met in the last universe they had jumped to. This Sans didn’t seem to be a scientist. Frisk didn’t know what his job was. A skeleton that dresses nicely and works in a warehouse? A night guard maybe? Despite the circumstances, Frisk had to admit this Sans looked extremely handsome dressed like that. The silence went on long enough that they entertained the idea of what it would be like if their Sans got dressed up like that. Frisk would probably grab him by his lapels and kiss him.

“I understand that it’s . . . unbelievable,” Frisk shrugged a little bit, “but it’s a _frisk_ you’ll have to take.”

Sans blinked once, his face no longer the blank contemplative look he had been sporting. His smile became slightly more genuine. He seemed to reach some kind of conclusion as he stepped back out of Frisk’s personal space. “you’re alright, kid.” Frisk wasn’t sure how they felt about this Sans calling them a kid. “guess you get your jokes from the other me.”

“He taught me a few _rib-ticklers_.” Frisk agreed, trying to keep their face straight. They succeeded for the most part. Sans’s eyes crinkled with amusement, unable to help a good joke. He really was Sans through and through, after all.

“crackin’ jokes at a time like this? you’ve got some _guts_ , kid.”

“It takes some _spine_.” Frisk agreed.

“got a good _backbone_.” There was a beat before Frisk couldn’t resist anymore and they started giggling, covering their mouth to muffle the sounds. Sans watched them, eyes darting around their form as he took them in. Frisk saw his huff of laughter, though.

“SANS!! I CAN HEAR YOU PUNNING! ARE YOU PRACTICING AGAIN? YOU’D BETTER NOT BE TEACHING LITTLE PUP PUNS!! IT’S BAD ENOUGH YOU AND OLD BOSS ARE DORKS!” Frisk blinked in surprise to hear Papyrus’s voice. Was he also a night guard here? Sans shot one last assessing look at Frisk before he turned towards where his brother’s voice was coming from.

“hey bro, come take a look at this.” He said. Frisk relaxed understanding they were off the hook for now. They had expected more interrogation, but Sans had said they were on a schedule. They probably had to go back to their rotations. Why had Frisk’s other self been there? Were they also a night guard? Papyrus had mentioned a pup. Did they have a dog too?

Papyrus jogged around the corner and came to a stop at the sight of Frisk. He was also dressed nicely with his dress shirt and pants, suspenders, and tie. His clothes were nice and pressed. Frisk rather thought he was handsome too. “WOW! ANOTHER DOG! IN OUR WAREHOUSE?” Frisk blinked. Dog?

“yeah. just found ‘em.”

“THEY LOOK LIKE LITTLE PUP!”

“maybe they are. it’s the kid all grown up, it looks like.” Sans suggested, watching Frisk.

“HELLO THERE, BIG LITTLE PUP!” Papyrus walked forward and took Frisk’s hand, giving it a quick shake. “I DON’T KNOW WHAT HAPPENED TO MAKE YOU SUDDENLY BIG, BUT I’M GLAD YOU’RE OKAY!”

Papyrus thought that Frisk was this universe’s Frisk. It looked like Sans wasn’t about to correct him. How young was Frisk’s other self in this universe? And why did Papyrus think they were a dog? Sans at least knew they were human. It was all very confusing. They smiled at Papyrus a little, causing Papyrus to give a tiny gasp.

“YOU’RE SMILING! THIS IS WONDERFUL!”

Sans walked past Papyrus towards what appeared to be the entrance to the building. “bro, we’re gonna be late.”

“OH! YOU ARE RIGHT!” Papyrus cried, hurrying after him. Frisk watched them unsure about what they were supposed to do now. They shifted from foot to foot about to follow the brothers when Sans called,

“you too, kiddo.”

“WHAT? SANS, IT’S TOO DANGEROUS TO BRING BIG LITTLE PUP!” Papyrus protested.

“we can’t leave the kid unattended like they are.” Sans winked at his brother, shrugging. “they may change ages again.”

Papyrus rubbed his jaw and hummed with thought. Frisk didn’t know what the brothers were up to, but they certainly would rather join them then hang out in the warehouse. They didn’t want to be abandoned in a strange universe. They hurried to join the brothers. That seemed to make up Papyrus’s mind.

“ALRIGHT. BIG LITTLE PUP, YOU MAY COME WITH US! JUST BE SURE YOU STICK VERY CLOSE TO US!” Papyrus took Frisk’s hand and led them along. Frisk wasn’t used to Papyrus being the one to hold their hand, but they didn’t fight his hold. They considered also holding their other hand out to Sans, but they had a feeling they would be rejected. The thought saddened them a bit. They hoped that Sans was having good luck with their counterpart.

* * *

There was a child in his lab. A human child. A human child where Frisk had been quite literally a moment before. The kid looked dazed on their hands and knees, startled by their surroundings as they looked around. They looked exactly like Frisk did when they were younger, except, of course, this Frisk looked even younger. Probably closer in age to eight rather than twelve, if Sans knew his human ages right. They were dressed in what looked like one of Alphys’s sailor uniform cosplays. They were squinting a lot.

Sans stared at the human, quickly assessing what all could have just happened. Theory 1: Frisk just turned into a child. Evidence? Frisk was a child again. And this was definitely Frisk. Or, at least, _A_ Frisk. Theory 2: Frisk had somehow been zapped to another universe. Again. Frankly that was probably more likely. Sans didn’t have any sort of technology needed to turn a person into a child. If that was even possible.

Sans kneeled before the kid, catching their attention. They only seemed a little surprised to see him. Which meant, at least, this Frisk was used to this version of him. “you okay, kid?” He asked, holding out a hand. The child took it and stood with Sans, but they stumbled a bit. Their face was pale. Whatever caused them to arrive here had clearly disoriented them.

They gripped his jacket and stared at Sans for a long time, blinking steadily. Sans almost asked why they were staring when their head ticked just a little to the side. Ah, they were confused. It seemed that all Frisks picked up that quirk. Sans wondered what was so different about him.

“you dizzy?” Sans asked, brushing back Frisk’s hair just to check and make sure they hadn’t hurt themselves somehow. Frisk didn’t respond. They didn’t shake their head or anything. Sans glanced towards the stairs leading out of the basement. Frisk continued to stare at him for a long time before looking around the room. They seemed fascinated but still confused. Sans grabbed their hand gently and tugged them to follow him. Frisk went easily, going back to staring at him as they headed towards the stairs. They struggled a bit to climb up the first couple steps, but then they stopped trying. When Sans looked back at them, they were holding their head. So they were still dizzy.

Sans didn’t really relish the idea of carrying a kid half his size up all of these stairs, but he wasn’t going to force the poor kid to climb the stairs if they weren’t feeling good. “c’mere, frisk.” He called. Frisk blinked at him as he lifted them and pulled them to his chest before awkwardly maneuvering them to scramble onto his back. It was a little unwieldy, but Frisk didn’t protest at least. They had yet to say anything at all. Were all Frisks around this age so quiet? Sans could somewhat recall that Frisk didn’t talk very much when they had first met. It made Sans wonder about where the kid lived.

He climbed the stairs and glanced around the kitchen, kicking the door to his hobby lab closed behind him. “hey pap?” He called.

“I’M IN THE BATHROOM!!” Papyrus shouted from upstairs. Sans could hear some scrambling and a faint growling sound. “HOT CAT HAS TAKEN POSSESSION OF MY HAIRBRUSH AND WILL NOT RETURN IT!!”

Great. Sans had to climb even more stairs. Frisk at least was being good, hanging onto his back. He could feel them shifting as they looked around themselves, but other than that they held still. Sans looked over his shoulder at them.

“you feelin’ any better?” He asked them. Frisk gave a tiny nod. Sans set them down on the ground. They were steady as they stood. That was good. It didn’t appear that there were any lasting side-effects of the switch. Sans motioned over to the couch. “grab a seat. i’ll be right back, okay?”

Frisk did as they were told. They struggled to get on the tall couch, but they managed to shimmy their way up there. Sans would’ve helped them, but frankly they looked adorable with that determined face on them. He hadn’t realized how cute they used to be. Not that they weren’t still cute now, but like this Sans really couldn’t get over it. The outfit didn’t help. Whoever put the kid in that outfit had good taste.

Hot Cat hissed from upstairs, and Sans heard Papyrus cry out. Sans looked up just in time to see the hellbeast streak out of the bathroom and down the stairs, leaping straight onto the bookshelf and knocking over the candle that was there. The candle hit the carpeted floor with a muffled thump. Hot Cat’s fur was puffed up, clearly in a snit. Sans was tempted to make it worse.

Papyrus stomped out of the bathroom with a relatively mangled hair brush brandished angrily. “WHAT DID MY BRUSH DO TO YOU?” He cried to the cat. Hot Cat only glowered at him, tucked into the little space where the candle had been. Papyrus huffed, unfortunately just as used to Hot Cat’s antics as Sans was. Honestly, how long did cats live?

“big news, bro. or rather, _little_ news.” Sans jerked his thumb in Frisk’s direction. They were staring at the cat on the bookshelf, their mouth a little open in surprise.

“FRISK! YOU’RE A LITTLE HUMAN AGAIN!” Papyrus jumped down the stairs and hurried over to Frisk. The kid returned to their blank face, staring at Papyrus through mostly-closed eyes. Did the kid need glasses? Papyrus grinned, clearly delighted, before turning back to his brother. “WHAT HAPPENED TO THEM?”

Sans nodded his head once in Frisk’s direction. “s’not our frisk. looks like they got switched again.”

“OH WOW! ANOTHER FRISK!” Papyrus took Frisk’s hand and shook it. “HELLO, OTHER FRISK! I AM THE GREAT PAPYRUS!”

Frisk only stared at him. They seemed completely unsurprised. Sans wasn’t sure this kid even knew what was going on around them. They had yet to say anything at all, or to really even emote. He hoped that they were alright.

“QUIET ONE, AREN’T YOU? WHAT’S YOUR WORLD LIKE? AM I IN IT? DO YOU RECOGNIZE MY AMAZING SELF AND THAT IS WHY YOU ARE STUNNED INTO SILENCE? I UNDERSTAND, HUMAN. PLEASE, TAKE YOUR TIME!”

The kid still didn’t talk. Sans went into the kitchen and grabbed a snack for the human, just in case they were hungry. He didn’t hear any voices. By the time he came back with some yogurt, his brother and Frisk were still staring at each other. Frisk finally reached out and touched Papyrus’s cheek, but they still didn’t respond. Their face relaxed a little. That seemed to satisfy Papyrus as he swooped them up into a hug.

“SANS, LOOK! THEY’RE HUG-SIZED NOW!!”

“that’s great.” Sans said, hopping up onto the couch. Papyrus dropped Frisk back onto it before he joined them. Frisk bounced a little from the force of it. They seemed used to it. Sans opened up the yogurt. Frisk stared at him now. What was with this kid and staring? Why did Frisks have to stare? It was a bit unnerving. Sans knew he was a handsome guy, but still.

Then the human started to drool a little bit. Okay, Frisk never _drooled_ over him before. At least, not literally. Sans opened his mouth to make a quip when he realized that Frisk was staring at his yogurt. Oh, Frisk must actually be hungry.

“here you go, kiddo.” Sans offered the yogurt. Frisk didn’t take it.

“ARE YOU ALRIGHT, FRISK?” Papyrus asked. They continued to stare and drool. If anything, the staring became stronger. Could stares become stronger?

Sans tried again. “uh, just take it. you know what yogurt is, right?” What kind of strange universe did they come from? Was yogurt not a part of it? Maybe it was the brand.

Frisk opened their mouth and waited.

“THAT’S ADORABLE!” Papyrus cried, hopping to his feet to stand behind Sans for a better view of the situation. “THEY’RE LIKE A LITTLE PUPPY!”

Sans shot his brother an amused but confused look. “how so?”

“LOOK AT THEM! THEY’RE SO EXCITED TO BE FED!”

Sans wasn’t sure how he felt about feeding the kid. But they were still waiting. Maybe this was normal for them? He admitted that they did look rather adorable. He gave up and scooped some of the yogurt onto the spoon before feeding it to Frisk. They happily ate it, their face lighting up at the taste. Sans was glad to see some emotion there. Maybe the kid had just needed food this whole time.

Frisk crawled a bit closer, bouncing up and down a little in their excitement as they opened their mouth again. Sans fed them again. They were just as pleased this time.

“heh heh, maybe you’re right, bro. they are like a little puppy.” Frisk paused there, their eyes widening just a bit. A small smile formed on their lips. Maybe they liked the name?

“I LIKE THIS FRISK!” Papyrus decided. He rubbed Frisk’s hair cheerfully. “THIS IS A LITTLE PUPPY I CAN STAND!”

“yeah.” Sans agreed, bemused. He fed the kid another bite. They weren’t that young of a human. Was it strange for an eight year old to be hand-fed their food? Sans didn’t exactly have a frame of reference for it. He wondered what kind of universe the kid had come from. There were endless possibilities. Was their family waiting for them? Were they okay with a new adult Frisk showing up? Wherever they were, Sans hoped that the kid was okay.

* * *

Sans and Papyrus were not night guards. They were into illegal activities. And Frisk was now an accomplice.

The brothers had taken Frisk straight away to some kind of warehouse on the far side of town. The entrance had been secured by a large metal door that didn’t look very passable. Frankly Frisk thought it wasn’t subtle at all. It practically screamed “IMPORTANT THINGS IN HERE. DO NOT ENTER.” Apparently this Sans and Papyrus were going to ignore the warning. Frisk wondered what kind of activities their other self was wrapped up in. And how these two brothers had become criminals. Maybe becoming royal guards hadn’t worked out.

“guards must be switching.” Sans noted.

“WE’RE STILL ON TIME THEN.” Papyrus’s voice was lowered, but still rather loud to Frisk’s ears. If they were trying to be sneaky, they’d best hurry. Frisk thought about what their mom would say when she found out about these activities. They were so in trouble. Maybe they wouldn’t tell her about this little misadventure. If breaking and entering could be called a misadventure. Well, it wouldn’t be the first time Frisk had illegally broken into somewhere with a Sans.

“i'll go first then.” Sans straightened from his crouch. He made seemingly casual eye contact with Frisk, commanding them to stay close to Papyrus without a word. It seemed they still weren't trusted. They supposed that was a reasonable reaction. Frisk nodded. Once his message was across, Sans strolled forward two steps before disappearing entirely. Frisk stiffened with surprise. They couldn't sense a shortcut there at all!

Papyrus grabbed Frisk's hand and tensed. His entire body, though serious, radiated enjoyment. He grinned at Frisk. They thought they heard a small knock against metal, but they didn't have time to question it as Papyrus lept to his feet and rushed to the door with Frisk dragged on his heels. He only slowed a bit when Frisk stumbled, but they righted themselves swiftly. The large door was open just enough for both of them to squeeze through. Sans was on the other side leaning on his shoulder against the door casually. He seemed amused by Frisk's baffled amazement.

Papyrus closed the door quietly and faced his brother. Frisk remained silent but looked around. They were surrounded by crates, but they easily recognized the dangerous crackle of electric fencing. Why were there electric fences in a warehouse? What kind of items were stored here? They looked at the brothers to see what they were waiting for. Sans pointed upwards and Papyrus nodded.

Both Frisk and Sans watched as Papyrus jumped, gaining height with an ease that could only be provided by blue magic. He hopped from box to box, keeping his head low. Frisk wondered what he was doing. He landed on one of the taller boxes and put a hand above his eyes like a visor to scan the room. Looking for security guards maybe? Frisk wished that they weren’t so lost. They would ask the brothers, but they figured that such a moment was not the time to ask questions. They would rather go home than go to prison.

“this way.” Sans interrupted their gaping, motioning for them to follow him. The two of them ducked around some boxes, keeping low and into the shadows. Frisk still didn't have a clue about what they were doing until they came across a control panel. There were multiple buttons labelled with numbers and letters. Sans glanced a little upwards and Frisk followed his gaze. There were a couple of carpal bones floating there, clearly influenced by blue magic. Frisk gaped a little at them. They had never seen the brothers use such tiny bones before. Frisk couldn’t even see Papyrus from where they were, so it was amazing that he could manipulate the bones from where he was.

The bones began to spin and move. Sans paid close attention as the bones formed first the letter R and then a 3. Sans pressed the corresponding buttons. The ground vibrated just a bit, but Frisk couldn’t hear what was happening. They gently grabbed Sans’s shoulder as they leaned around him to watch him. He stiffened at their touch briefly, looking at them. Frisk tilted their head in confusion. Sans relaxed slightly and nodded back the way they came from to find the control.  
“go look.” He suggested, amused. “just stay quiet.”

Frisk considered instead staying and asking him why they were here and what they were doing breaking and entering, but they figured Sans would appreciate it more if there wasn’t a distraction hovering around him. He probably didn’t trust them, but they could just look around the corner so that Sans would be able to still see them.

Frisk hurried quickly across the floor and glanced into the main part of the room. They could just barely see Papyrus, his hand held out to the side and glowing with his magic, as he looked around at something. As they watched, the crates all began to move separately. They would fall into openings in the floor that Frisk had not noticed from this angle.They finally spotted the source of the electricity. Without the crates cutting off the flow, a person wouldn't be able to get through.

It was a puzzle! Was this a monster warehouse? Did monsters in this world have a strange love of puzzles too? What could the puzzle possibly be hiding? Or maybe they needed to move everything to move forward?

The brothers moved quickly together to clear a path with the crates. Frisk blinked as a door on the far side of the room was revealed from behind the seemingly last crate. Papyrus landed next to Frisk, startling them at his sudden appearance. He grinned and held out his hand to them. “COME ON, BIG LITTLE PUP.” Frisk took his hand (although they really didn’t feel it necessary for him to lead them around) and followed after the tall skeleton. Sans was already by the door, walking through it right as Frisk and Papyrus joined him. They entered after him.

The room was large and lined wall-to-wall with inlaid metal boxes. Frisk was reminded of a bank vault like they had seen in the movies. Papyrus was already moving towards a safe in the middle of the room while Sans stood near the door, looking out of it. He motioned for Frisk to follow Papyrus. Frisk still felt a little unnerved about this. The brothers must be thieves, but why? What would be the point? What had led them to the life of crime?

Frisk wasn’t sure if they were more surprised that their friends were criminals, or that Sans was actually doing something. Well, doing something while still doing nothing. Truly he was a master of slacking off.

They joined Papyrus and kneeled down in front of the safe as the skeleton spun the lock swiftly but cautiously. Frisk didn’t know anything about breaking open a safe, but apparently Papyrus had a lot of skill with it. His hands were unhesitating, only pausing when he slowed the turning to find to right number.

The safe popped open within moments. Papyrus gave a quick cry of triumphant delight as he pushed the door open. Frisk goggled at the sight of packages of jewelry, each wrapped up carefully and looking ready to be shipped off. Or they had just arrived and hadn’t been unpacked. Sans joined them, pleased.

“good job, bro.” He nudged his brother as he reached in and grabbed a gorgeous jade hairpin while Papyrus dug around to pull out two rings. The brothers held the items out to Frisk. Frisk hesitated only a moment before they took the priceless jewels and pocketed them. They were glad they had worn their large capri pants. Plenty of deep pockets. They were now a legitimate accomplice in this crime. Surprisingly the brothers left the rest of the stuff alone, dismissing the items by closing the door. Sans spun the lock carelessly. Weren’t they thieves? Why were they ignoring all of the jewels?

“THAT WAS EASY!” Papyrus ran a hand over his skull as he looked around the room.

“better hurry back.” Sans warned. “the guards are supposed to circle around about−”

The door burst open with a clamor, bouncing off the metal walls and causing Frisk to startle. A group of four monsters stood in the doorway gaping. They were all humanoid monsters that reminded Frisk of the guards they’d met in Hotland. They were just as fit too. “Shit! It’s the skeleton brothers!!”

“uh oh.” Sans muttered.

* * *

The first thing Sans did after he finished feeding the kid was to take them to Toriel. It wasn’t that Sans didn’t think he could take care of the kid . . . it was that Sans wasn’t sure he could take care of a kid. Frisk stuck close behind Sans and Papyrus as the three of them walked to Toriel’s house. The little kid kept looking around them, taking in the world. They stared when they saw other humans and startled when a car passed them by, but otherwise didn’t react to anything. However Sans was well-aware that they were keeping a little too close to him. He almost expected them to step on his slippers.

Sans glanced over his own shoulder at Frisk. They were watching a parent-child duo across the street. the impulse to mess with them was suddenly too great as he stopped dead in his tracks. Frisk ran straight into him and bounced back, falling onto their bottom. Sans snorted, covering his mouth at the startled expression on their face. Okay, they were _really_ adorable.

“SANS!” Papyrus scolded immediately, grabbing Frisk under the armpits to lift them up and comfort them. “DO NOT WORRY, FRISK! DON’T CRY!” Frisk wasn’t anywhere close to crying. However, they did allow Papyrus to pat their back and bounce them soothingly like they were five rather than eight. This was a good reason why Sans didn’t think they should be left alone with a child at this age. Papyrus was trying his best, but neither brother knew how to care for a little one.

Papyrus placed Frisk back on the ground once they were suitably soothed and he straightened their outfit. Frisk hadn’t reacted that entire time. They had yet to speak or make a sound either. Sans was seriously starting to wonder if this Frisk was mute. Or if something else was wrong with them. He wasn’t used to Frisk being _this_ quiet. That emotionless face teased at the edges of some of his more horrifying memories. He shook it off quickly. He didn’t need to think about that stuff. The trio continued without incident to Toriel’s house.

Papyrus didn’t bother to knock as he opened Toriel’s front door. “HELLO!” He called loudly.

“I am in the sitting room, boys!” Toriel responded. Papyrus ran past the entrance. Frisk continued to stick close to San’s hip as the two of them followed after the taller skeleton. Toriel was sitting in her favorite chair with some knitting in her lap, but she was instead reading a joke book. Sans was pleased to see it was the book he had gotten her for Adult Day. She had been talking about how she had wanted to read it but hadn’t had the time. She smiled at the sight of them, and then froze as her eyes landed on Frisk. “Um,”

“dunno how yet, but seems like frisk’s been sent to another universe again.” Sans placed a hand on Frisk’s shoulder and nudged them forward. They moved just enough to stand by his side. They didn’t seem especially nervous, but they were still being a little clingy. They were holding their right arm as they gazed upwards at Toriel.

“Oh my.” Toriel placed aside her items to stand up and approach them. “How did this happen, do you think? This is certainly not the same Frisk as from the other universe.”

Sans had a couple of theories already running around inside of his skull, but certainly nothing substantial. The most likely one at the moment was that Frisk was somehow unstuck from this universe, which would be a horrible thought. The kid had enough problems with time, let alone space.

Sans closed his eyes and shrugged. “i only got guesses, tor. i’ll look into it with alphys, but for now we’re stuck with this lil pup.” He patted Frisk’s head. They turned to gape at him now with surprise. More staring it seemed. But then a smile broke out on their face, immediately making them seem even younger. Sans grinned back, unsure of what he said to make them smile like that.

“THEY THINK THEY’RE A LITTLE PUPPY TOO!!” Papyrus cried, excited. He fell to his knees beside the human, catching their attention. Their face dropped back to their usual impassive look. Sans and Toriel watched the interaction, both noticing how quickly the human had responded to being called a puppy. A nickname maybe? Sans would’ve never considered calling Frisk a puppy though. Maybe the Papyrus of that world had done it. That seemed much more likely.

Papyrus had grabbed Frisk’s hands, doing a little dance with them as he kept repeating the word “puppy” over and over again. It was a cute little scene to see his tall brother awkwardly trying to dance with someone so small while he was on his knees. At least they were closer in height that way.

“you mind watchin’ the pup while they’re here?” Sans asked, turning back to Toriel.

Toriel gave him an amused smile. “They _are_ my child, Sans.”

Sans waved his hand. “just thought i’d ask.” He paused and continued to watch the scene. Papyrus had gotten Frisk to do some kind of waddling dance, throwing their hands up into the air. They seemed to be having fun from what Sans could tell. “just a head’s up, though. i’m not sure if the kid can speak.”

“What do you mean?” Toriel asked, alarmed.

“well we’ve had the kid for a little while now and they haven’t said a word. not even sure if they can completely understand us, to be honest.”

“Maybe they speak a different language in their universe?” Toriel tapped a claw to her lips, considering. “Perhaps we should make the effort to communicate with them. They seem to already know the both of you.”

Papyrus released Frisk, who spun around a few times looking dizzy. They came to a stop and widened their eyes as they tried to regain their bearings in the spinning world. Papyrus stood up with a satisfied air about him. “I’M GONNA CALL THEM LITTLE PUP!”

“We can tell.” Toriel chuckled considering Papyrus had been saying the name repeatedly for a bit.

“I THINK THEY LIKE IT! AND IT WILL HELP US TELL WHICH FRISK IS WHICH WHEN WE TALK!”

Sans shrugged. “okay.” He was pretty sure they all knew which Frisk they were all talking about when they talked, but he wasn’t exactly going to tell his brother no. Besides, little Frisk seemed to respond better to it. Maybe it was the way the name sounded. He decided to test it out. “hey come here for a sec, lil pup.” Frisk responded to the name, trotting over when he motioned to them. He shouldn’t have motioned. Now he wasn’t sure if Frisk understood him or not.

It felt weird calling the kid a dog. It may be better if Frisk never found out about that nickname.

Toriel was once again kneeling. She placed a large paw on Frisk’s shoulder (although most of her hand had their arm rather than their shoulder. “Do you know how to speak, little one?”

Frisk didn’t respond, only staring at her. Toriel glanced at Sans. Sans only watched her.

She tried again. “Do you understand who we are?”

“don’t be rude, kiddo.” Sans added, hoping to provoke them into talking. “answer the nice lady.”

“YOU DON’T HAVE TO TALK IF YOU DON’T WANT TO, LITTLE PUP! NODDING OR SIGN LANGUAGE WILL WORK TOO. WE KNOW THAT!” Papyrus inserted.

Frisk didn’t respond again for a long moment before they finally nodded. Papyrus’s face lit up. Sans was just relieved that they seemed to understand them. It would be bad if this poor Frisk was trapped among monsters they couldn’t even understand.

“guess that means they’re mute.” Sans reached forward and brushed Frisk’s hair out of their face. “at least we don’t need to find a way to talk to them.” He nodded to Papyrus. “you mind callin’ alphys? we gotta head over to her lab. give her a head’s up.”

“SURE! I NEED TO BLOG ABOUT THIS ANYWAY!” He left the room.

“Is that smart?” Toriel asked Sans quietly.

“nobody believes that stuff anyway.” Sans reassured her with a wink. “‘s all sci-fi. anyway pup,” He told Frisk, “let’s go see your room.”

* * *

The monsters looked angry. Frisk was used to dealing with angry monsters, but they weren’t used to dealing with so many angry monsters with so many weapons. They looked over at the brothers, but neither of them seemed especially worried. They both stood up and brushed themselves off casually despite the growling coming from the hulking monsters.

“GENTLEMEN.” Papyrus greeted.

“you’re back early.” Sans added.

“Get them!” One of the monsters called instead. They charged at Sans and Papyrus. The brothers both dodged the initial swings of their attackers and summoned a bone each. Papyrus spun around and whacked the baton from the monster’s hand, sending it flying across the room. The monster barely had time to comprehend his weapon was missing before they were knocked out by a hard attack to the head. Frisk flinched a little at the sight. It wasn’t horrible, but it was certainly more violent than they were used to seeing from Papyrus.

Sans went in the opposite direction, dodging backwards from each successive swing. Light blue magic coated the bone before he threw it hard at the monster’s head. They wisely froze, but the one behind them didn’t see it coming. They were thrown from their feet. Sans shot a wave of bones at the one who had dodged, forcing the monster to back away from the skeleton.

Frisk stood there, unsure of what to do. Obviously they were all caught red-handed, but was there a way out of this peacefully? They didn’t want anybody to die. Frisk took a breath and rushed into the fray, summoning their Soul in preparation for any magic that they would need to do. The monster leader of the guard seemed startled as Frisk charged at them. They raised their weapon, but Frisk held up their hands. They didn’t want to fight. The monster paused, lowering their weapon a little in confusion.

Frisk struggled to find something to say considering they were clearly in the wrong here, but they had to try. “We don’t have to fight.” They attempted.

“Are you kidding me?” The monster cried, outraged, and brought up the gun. Frisk gaped. They didn’t realize that monsters even used guns.

“LITTLE PUP!!” Papyrus cried out. He sent one of the guards flying against the wall while Sans dodged under the swing of another’s attack. Both of them were focused on Frisk, working to get to them.

Frisk didn’t hesitate. They didn’t have to play by the “rules” of fighting considering the monster hadn’t initiated the battle. With just a quick thought and a wave of their hand, their Soul turned bright green and a shield appeared in their hands. They brought the shield up just in time for the monster to fire off three rounds. The magical shield took all of the hits, completely unaffected. Frisk definitely felt the attack a lot more though. Their arm ached with each successive hit. Were monsters stronger in this world? Guns could not be this powerful!

Frisk opened their mouth to try a different method to convince the monster to not attack again, but the monster was flung across the room with blue magic. Frisk could hear more monsters coming. Arms wrapped around the human’s waist and tried to lift them, but the green magic held Frisk fast. Papyrus was sweating as he tried again.

“release the magic, kid!” Sans called. Frisk did so immediately, and they were thrown over Papyrus’s shoulder in response. They let out a pained noise at the boney shoulder digging into their stomach. Blue magic was wrapped around their soul. Their hands immediately came up to wrap around the unprotected heart just in case. It caused problems for their vision, but if there were bullets flying they didn’t need one going straight into their Soul.

Papyrus was running then, head down and ignoring all of the monsters. They couldn’t see Sans at all. Frisk tried to make themselves as small as possible as Papyrus charge straight through the warehouse and out the door. The sounds of police sirens were on the air, but they were still far off yet. The other monsters were still nearby, shooting at them with both bullets and with magical attacks. Papyrus ducked into an alleyway a couple streets away to escape sight and fire and placed Frisk down. He grabbed their hand.

“CAN YOU KEEP UP WITH ME?” He asked quickly. Frisk nodded and didn’t even finish nodding before they were being pulled along down the road. Every now and again they ducked into alleyways or into paths that Frisk would’ve never known were there. Frisk didn’t know if they should be more scared of the police finding them or the gang they had stolen from.

Sans was waiting behind a decrepit building when Frisk and Papyrus arrived. Frisk had to pause to catch their breath, their face covered with sweat. They must have run for at least the past ten minutes. Sans and Papyrus nudged them forward, though, towards an uncovered hole in the ground. It seemed to be some kind of secret passageway. Frisk climbed down it without hesitation as the brothers followed right behind. They couldn’t see a thing once the door to the passage was closed.

They summoned a fireball then, glad for the light. Papyrus and Sans startled them as they appeared into the circle of light. “LITTLE PUP, YOU NEVER SAID YOU COULD DO MAGIC!” Papyrus cried, delighted. He seemed to have relaxed now. Maybe they were all safe there.

“yeah kid.” Sans’s voice was carefully guarded by his usual friendliness, “where’d you learn that?”

Frisk wasn’t sure if Sans wanted them to explain that they weren’t from the same universe again with Papyrus around. Now that they thought about it, they probably seemed a lot more suspicious to monsters for being able to do magic. They didn’t know how humans were in this universe. Perhaps it had been a mistake to do magic around the brothers. Just because they looked and acted like their friends, didn’t mean they were so accepting. What were the stories of the monsters in this world?

In the end they didn’t respond, too unsure of what Sans expected them to do. Instead they held out their hand for Papyrus to take, already expecting him to lead them.

He did take their hand again. “SANS, I THOUGHT YOU SAID THE GUARD WOULDN’T BE THERE? WE SHOULD’VE HAD AT LEAST ANOTHER THREE MINUTES.”

Sans looked tired in the firelight, beads of sweat on his head. He pulled out a handkerchief to wipe at his skull. Frisk recognized magical exhaustion. Teleporting must take a lot out of him, Frisk thought. “we must’ve been late because of the kid’s sudden growth spurt.” He glanced at Frisk.

“WELL NO MATTER! WE FINISHED THE JOB PROPERLY, RIGHT?” The human reached into their pockets and showed them the stolen goods. Papyrus nodded at the confirmation. “THAT WAS A LOT EASIER THAN EXPECTED CONSIDERING WE BROUGHT THE BIG PUPPY.”

“not bad at all for your first run, kid.” Sans praised. Despite the reason for the praise, Frisk felt happy. Maybe they were starting to gain Sans’s trust? They doubted that such a small thing would do it, but they certainly hoped for it.

* * *

Papyrus had called Alphys, but she didn’t pick up. Judging by her blog, she was out on a date with her wife. Which was fine, but Sans had wanted to start work on the idea he’d had in mind. The last time that Frisk had gone to another universe, Sans had gotten the idea to maybe make a device of his own that would allow him to go to another universe. Only without switching places with his other self. He’d allready had the idea of how to do so in mind, and he’d had plenty of time while on the road trip to think about it. That being said, he didn’t know exactly how he would build it. He had the science down, but not necessarily the technical expertise. Which is why he had wanted Alphys’s input and possible help.

However it seemed that he was stuck focusing on this universe for the time being. The night had dragged on, but Alphys had yet to respond to Sans’s text. He and Papyrus had decided to spend the evening with Toriel watching how she interacted with the child. Frisk didn’t actually attach themselves as quickly to the motherly monster as Sans expected. They paid attention to her when she talked to them and they helped out with dinner, but afterwards they always seemed to gravitate back to one of the brothers’ sides.They had yet to say a word the entire night.

Toriel didn’t seem overly concerned, but she did keep an eye on the child. She kept attempting to get Frisk to communicate more. She would ask questions that required answers, but she started to instead ask yes or no questions. Frisk only occasionally nodded or shook their head. Most of the time they just watched. Sans paid close attention to them and learned quickly that the kid’s facial expressions were more subtle than he was used to with his Frisk.

He wondered about the world this Frisk was from. Obviously they knew some form of him and Papyrus (and maybe Toriel? Perhaps they were just courageous) because they hadn’t appeared to be the least scared of them, but what was the world itself like? The only other Frisk Sans had met had been the same age as his Frisk. Did time travel differently there? Had this child gone through the underground at such a young age? Sans couldn’t particularly sense an extreme amount of knowledge from this child like he could from his Frisk.

When the food was actually made, Frisk didn’t immediately go for their own meal. Instead they stood by Sans expectantly, staring at him while he tried to eat. Toriel and Papyrus gazed at Sans in confusion, and he shrugged having no idea why the human was staring.

Frisk placed their hands on his leg and stared at the meat on Sans’s fork. Drool gathered at the corner of their mouth. Their gaze turned longing. Sans shot his friends an amused look before asking the child, “you want some of this?”

Frisk opened their mouth wide. Who took care of this child back in their world? They were more like a dog than Sans had been expecting. Maybe his brother was onto something here. Sans popped the food into Frisk’s mouth for them to try. They munched on it happily and swallowed before opening their mouth again for more. Sans was fully prepared to shoo them off to the chair where their own plate of food was waiting, but they were hopping up and down excitedly again. It was the most lively Sans had yet to see this Frisk, even counting the yogurt incident earlier. Plus they looked adorable. Sans was reminded of a chick. He fed them again.

“Frisk?” Toriel called, “Come join me over here. I will feed you my child.” Her voice was laced with laughter. “Let Sans eat in peace.”

Frisk paused from their hopping and begging, seeming to consider Toriel’s offer. They gazed at Sans’s food longingly before they reluctantly walked over to Toriel. The chairs −built for tall monsters− were far too high for Frisk to climb up onto, so Toriel had to lift them into the seat. There were already plenty of items there to lift the child higher considering even adult Frisk needed at least one of them to sit comfortably at the table. Sans needed one too.

Toriel attempted to feed the pup just like Sans had, but Frisk didn’t open their mouth. They stared blankly at Toriel and refused to eat. Toriel frowned, more confused. “What is the matter, my child? I assure you it is the same meal.” She gently attempted to feed them again. Once again Frisk refused to eat it.

“maybe they only like to be fed by a sans?” Sans suggested, mostly as a joke. He took a bite of his own food. The kid was staring at his food again, an almost-betrayed look ghosting across their features as he ate. “dunno why that would be a thing though.”

“WHY DO ALL OF THE FRISKS LIKE YOU BEST?” Papyrus complained. He reached out with his own food and attempted to feed Frisk. “HERE YOU GO, LITTLE PUP!” Frisk didn’t react to the offering. Papyrus sulked for .2 seconds before his phone went off. He checked it, successfully distracting himself from being sad at Frisk’s rejection of his food.

Frisk instead picked up their fork and took a bite of their own food finally. Toriel sighed, disappointed. “Well . . . at least it is good they can feed themselves. You cannot be the one to feed them every time.”

“definitely.” Sans finished his meal fairly quickly, not hungry. He glanced at the clock. It was getting pretty late. Papyrus was rapidly texting on his phone. Sans leaned on his elbow with a grin. “sup, bro?”

“NOTHING AT ALL! I JUST NEED TO GO INTO WORK TOMORROW MORNING.” Papyrus pocketed the phone with a cheerful look on his face. Sans was proud of his brother for finding a job that he was passionate at. Not that Sans expected his brother to give anything less than 102% at whatever he decided to do with his life.

“You two should hurry home soon, then.” Toriel picked up the finished dishes and carried them to the sink. Frisk slid off of their chair and landed a little roughly on the ground, stumbling from the height, before they wandered over towards the bookshelf closest to Sans. They were eyeing the some of the more colorful bindings. That reminded Sans that he needed to feed Hot Cat when he got back home. Chances are the thing finally got off of the bookshelf.

“yeah, probably.” Sans slid off of his own chair.

“COME HERE AND GIVE US A GOOD NIGHT HUG, LITTLE PUP!” Papyrus called. Frisk turned around and hurried over to his side. Papyrus got down to their level and opened his arms. They hesitated only a moment, as if expecting Papyrus to hug them first, before they moved the final distance to initiate the hug. Papyrus squeezed them tightly before releasing them to his brother. Sans hugged Frisk and gave them a quick kiss to their hair out of habit. When he released the kid, they were touching their head curiously.

“i’ll stop by in the morning, tor, if that’s cool.” Sans told the woman. She nodded.

“Please feel free!” She gave Sans and Papyrus both a quick friendly hug before they all walked to the door. Sans rubbed Frisk’s head.

“see you tomorrow, squirt.” Papyrus waved goodbye too and exited. Sans followed. Frisk moved to hurry after them.

“No, Frisk. You are going to stay here with me tonight.” Toriel gently captured them in a playful hug and scooped them up effortlessly. Frisk blinked at her in confusion. Toriel made a bit of an over-exaggerated face. “My, when was the last time you had received a bath, my child? Come, let us get you to the bath now.”

Frisk looked at the departing backs of the brothers and wiggled, distressed. Papyrus glanced back and saw them struggling. “SANS, LOOK.” Sans looked. Frisk was waving their arms at them, clearly wishing to join them. Sans gave a short wave back to reassure them.

“They will return tomorrow, Frisk.” Toriel attempted to calm the child, but they continued to struggle. The brothers were still leaving.

“Sans!” The child cried out, “Pap!” Both the brothers and Toriel froze, the former spinning around to stare at the child they had been certain was mute. Frisk seemed a little more calmed seeing they had caught their attentions again. “Sans?” They called again.

Toriel gave Sans a helpless look. “It appears they want you to stay, Sans.”

“maybe you were right about the frisks, papyrus.” Sans muttered to his brother.

“CAN I STAY TOO?” Papyrus instead called to Toriel, already excited at the possibility of a sleepover. He ran over and scooped Frisk out of Toriel’s arms, spinning them. “WE WILL HAVE SO MUCH FUN WITH LITTLE PUPPY FRISK!”

Sans had wanted to go and work tonight on some of his calculations for the possible multi-dimensional machine he’d hoped to make. However it seemed that the choice had been taken from him. He could work on it later when the kid finally fell asleep. Sans didn’t think he was going to get much sleep that night. Besides, he was used to having a body to sleep next to now. It would be strange not to have someone there.

 _“Look, Sans.”_ His Frisk would probably say at this moment, laughter in their voice. _“Even other versions of me love you.”_

Sans shook his head to dismiss that thought. The little kid was still staring at him from Papyrus’s arms. Sans closed his eyes and gave up with a sigh, moving to join Toriel and his brother. Well, it was just for a little while. The kid was probably just scared to be in a new place. If it helped to calm them down, he would stick around. Hot Cat would survive the night.

* * *

Frisk learned quickly that these brothers didn’t have any sort of bed. Not even a single one. They had a couch. According to both of them, that was clearly enough. Frisk didn’t understand it. They wondered where “Little Pup” slept then. They could only assume that clearly the other version of them was smaller, but sleeping on a couch couldn’t feel that good. They hoped that their other self was significantly smaller. Maybe even a child. But then again, Frisk wasn’t so sure how to feel about this Sans and Papyrus (two criminals) taking care of a child. Frisk had never felt any sort of parental feelings towards a child before, but they found themselves worrying. Maybe it was a Dreemurr trait. They could already hear their mother’s distraught cries at the thought of a child sleeping on a single couch with two criminal skeletons.

Sans had sent Papyrus off to do whatever it was they were going to do with the stolen goods. Frisk didn’t need to know how these brothers operated to know that Sans had sent his brother off on purpose to get Frisk alone again. Honestly rather than all of this deceit it would be easier if Sans just admitted to Papyrus that this Frisk wasn't their Frisk. They had forgotten what Sans was like before he trusted his brother with all sorts of knowledge.

“so.” Sans started after his brother had gone. Frisk guessed that Papyrus wouldn’t be gone too long if Sans didn’t have time to verbally beat around the bush. Either that, or this Sans jumped to the point faster. They didn’t have enough experience with him to tell. “humans can do magic? ‘s first i’ve heard that.” His voice had that dangerously light tone to it again. Frisk would need to step carefully. They didn’t know the history of this world, but it seemed that it was different from Frisk’s world. There all monsters knew that humans had the potential to perform magic, but just didn’t know how to. Was Sans being deliberately obtuse, or was it because humans weren’t known to be able to perform magic at all here?

Frisk banked on the latter. “They can, but have forgotten how to. My family taught me.”

Sans raised an eyebrow at that. “monsters? or humans?”

“Monsters.” Frisk confirmed. “I don’t live with my human parents anymore.”

Sans didn’t press that information. “what kind of magic do you know?” He asked, honestly curious.

Frisk summoned their Soul again, catching Sans’s attention. He stared at the bright red Soul with guarded curiosity. Frisk showed him some of the magics they could do, including the various color magics and the summoning of fire. They also decided to pull out some food (they were honestly hungry from all of the running and excitement) from their portable space. Sans seemed reasonably impressed.

“what’s that?” He pointed at Frisk’s Soul.

Frisk released their Soul, allowing it to sink back into their chest. “My Soul. I can’t perform magic without bringing it out.”

Sans shoved his hands into his pockets, leaning against the side of the couch Frisk was sitting on. They opened their bag of popato chisps and popped one into their mouth. They felt the little bit of health they had lost from the gunfight return swiftly. They hadn’t even realized they had lost any health. Their arm still kind of hurt from it. They would probably be sore in the morning.

“why would you need to summon your soul? seems dangerous.”

Frisk rolled around their answer in their head. “Usually,” they said slowly, “a monster would initiate a battle first. Which would expose both opponents’ Souls to danger. Though it isn’t unusual for smaller battles to ignore it. There aren’t any . . . official ‘rules’ for such things. It’s just . . . proper.”

Sans looked away from Frisk, gazing at the wall. Frisk watched him. He looked so much like their Sans. They missed him suddenly. They wondered what he would say when they told him this story. Probably laugh at the thought of being a proper criminal. Would this Sans be amused of his counterpart’s various petty crimes? “that sounds pointless.”

“I think it’s intimate.” Frisk denied, recalling how personal a battle between souls could be.

Sans shot them a look. “interesting choice of words.”

Frisk shrugged, finishing their chisps. They tossed the empty bag back into their hammer space. They made eye contact with Sans before they smiled slyly. “I don’t mind getting up close and personal with some monsters.” Their wink was quick and unintentional. They blamed their Sans. With this Sans dressed like that, how could they not flirt a bit?

This Sans appeared a bit thrown by the sudden come on. Frisk wondered if maybe they could get their Sans to dress up nicely like that sometime. “yeah? wouldn’t’ve expected that.”

Frisk stared at the little opening at the top of Sans’s shirt. They knew rather intimately that Sans liked to be kissed on his vertebra. Would this Sans like it too? It was tempting. “Things can become quite heated during a heart to heart. Or . . . soul to soul.” Their eyes met his again. “It only takes _carpal_ of moments before something special happens.”

Frisk could see they had Sans’s undivided attention, but they could also see the confusion over the situation hovering on his peripheral thoughts. Honestly he could be so easy to read like this. Frisk themselves were still a little thrown. Usually Sans would’ve started flirting back right now, even if it was only playfully. It had become a game between the two of them. It was strange to have someone who looked so much like their boyfriend not join in. Frisk found themselves very much amused by this Sans’s reaction though.

“i don’t think starting a battle like that would be _hand_ -y.” He responded. He seemed reluctantly mesmerized as Frisk scooted a little closer on the couch towards him. Frisk liked this game a lot.

“If you have a proper _hand_ -le on the situation it can be very . . . exciting.” Their voice turned just a hint breathier at the end. Sans’s face did something funny, and Frisk couldn’t hold back anymore. They ducked their head to hide their face in their hands and giggle. He had been so baffled! They hadn’t seen that look on Sans’s face before. They loved it so much. They wished that they could’ve taken a picture.

Sans didn’t make a noise for a long moment before he chuckled a couple times too. “never would’ve taken you for the flirtatious type.”

Frisk tried to control themselves and lifted their head. Their face was right next to Sans’s hip as he leaned against the couch. If this was a different Sans, Frisk would’ve wrapped their arm around his waist and would’ve buried their laughter into his magically-pudgy stomach. As it was they weren’t sure this Sans would appreciate it, so they didn’t. They smiled widely at him. He stared at them with amused eyes, though bemusement was still decorating the edges of his smile.

“It’s fun.” Frisk finally told him.

“to flirt with strange monsters?”

“You’re not strange.” Frisk traced the inlaid tired lines of Sans’s skull with their eyes. They weren’t nearly as deep as their Sans’s used to be, but it seemed that sleepy look would always be a part of Sanses everywhere. “I know you very well.”

Sans fell silent again, eyes assessing Frisk, before he looked back at the door where Papyrus had left through. He must be due back soon. “you’re too open.” Sans scolded softly. “how would you know if i’m anything like your sans?”

Frisk hung their arms over the couch, also staring at the door Papyrus was due back through. “I don’t. But you’re Sans.” That was all Frisk really needed. Besides, it wasn’t like if Sans killed them they would stay dead. Sans didn’t respond to that. Frisk tapped his thigh once, unable to resist touching him. They had to remember this wasn’t their Sans, but it was still extremely difficult not to be as touchy with him as they were used to. “Your Frisk . . . or Little Pup? Are they young?”

“yeah.” Sans didn’t seem to mind Frisk’s finger tapping against his leg. At least they could do that. “they’re still a little kid. or a ‘puppy’.”

“How did you meet them? The Underground?”

Sans gave them a confused look. “yeah. that's this place.” The history here _was_ different. “that how you met your monsters?”

Frisk nodded. “Although in my world, ‘Underground' is much more literal.”

Sans frowned. “what do you mean?”

Frisk considered the story of how they'd heard about the disappearances on the mountain and how they had come to meet the monsters. They didn't particularly feel like dredging up that story again right then. They shrugged. “Long story.”

Sans's eyes narrowed, but he allowed Frisk to avoid the question. Instead he asked, “who else do you know other than me ‘n papyrus? toriel?” Frisk nodded again. Sans hummed as if he was confirming a theory. “undyne? asgore?” Frisk nodded again. Sans paused longer this time before asking, “gaster?”

Frisk didn’t respond at first. Every Gaster’s story seemed to be different. What would this Gaster’s story be? “ . . . Yes.” They finally said quietly. Sans had gone tense beside them.

“How?” Sans demanded. His voice was significantly colder than it was earlier. Frisk lamented that the conversation had gone in this direction. It seemed Gaster was nothing good here.

“Sans worked with him. Then Gaster died. He tried to erase me.” Frisk didn’t want to go into more details than that.

Sans looked down at them. “erase you after he died?”

Frisk shrugged rather than responded, rocking their hand back and forth to show he kind of got it.

The air grew quiet and expectant. Frisk waited to see if Sans would speak, but he didn’t continue. Papyrus returned soon after announcing a completed job. He yawned widely and didn’t notice anything between Sans and Frisk, instead caught up in his stretching. “BIG LITTLE PUP,” he asked as soon as he had relaxed and approached Frisk, “ARE YOU TIRED OR HUNGRY? OLD BOSS WILL YELL AT US AGAIN IF WE DON’T GET YOU TO BED ON TIME, EVEN IF YOU ARE BIG NOW.”

Frisk wondered who their old boss was. They wouldn’t mind having an actual meal, but they weren’t so sure of what kind of food they would get. They were lucky they still had a store of snacks in their hammerspace for just such snacking emergencies. They shook their head in response to Papyrus’s questions.

“they ate a little bit while you were gone, bro.” Sans informed him. “though we should get to sleep soon. you have to be at the stand tomorrow, right?”

Papyrus nodded. “ABSOLUTELY! I’LL GET THE BLANKET.” Sans motioned for Frisk to scoot over until they were sitting in the middle of the couch before he sat down in the spot they had vacated. Papyrus soon bound back over with a blanket and tossed it over Frisk to block out some of the chill in the air before he settled down on the other side of them. Frisk blinked wondering how they were supposed to sleep on this couch with the two brothers. They had slept with Sans on the couch before, and they had slept with Papyrus, but they hadn’t slept with both brothers at the same time since they were younger.

Papyrus loosened his tie and unlaced his shoes to toss them both nearby. He must’ve been tired if he wasn’t even going to put those away. Frisk wondered what he had done with the rest of the day. Sans just unbuttoned his vest and tossed his own shoes in the same direction as Papyrus. Frisk decided to make the best of it and huddled down onto the couch, curling up in a way that was familiar to them to tuck their face into their legs. It wasn’t very comfortable, but they could make due.

They were half asleep when their body rocked sideways and they found themselves leaning against Sans’s chest. They murmured an apology and attempted to shift off of him, but Sans just placed a hand on their hair and patted their head. “s’fine.” He told them quietly. Frisk’s chest felt warm. Their legs were soon tugged so they were stretched out on the couch, their legs tangling with Papyrus’s long legs as he kicked them up. Frisk was thoroughly wrapped up by the brothers, but they were happy. Their worries about their younger self faded some as they recognized this feeling of love. Sans’s breaths were a familiar metronome that Frisk fell quickly asleep to, even as Papyrus’s snores began to vibrate the air.

* * *

Sans had an interesting predicament on his hands. It seemed that ever since little Frisk had exposed that they could, in fact, talk, they had decided to speak quite a bit. The problem was that they didn’t seem to know many words. Or if they did know more words than either Sans’s or Papyrus’s names, they didn’t say them. They tended to just point at something they wanted or brought it over to Sans. Papyrus would be upset that he missed so much of Little Pup’s activity, but Sans was sure to snapchat him some videos.

Little Frisk liked to follow Sans around and call his name. Not even for anything important either. It was just them saying his name over and over again. Sans was starting to wonder if they should change the kid’s nickname from “little pup” to “little chick”. He would admit that it was adorable how they would walk-hop behind him saying his name, but it was also kind of distracting. He had wanted to get some work done today, after all, but it seemed that Frisk had other plans.

Toriel had found the entire thing hilarious. She demanded that Sans send her all of the videos he took of the incident. She claimed it would be funny to show Frisk when they returned. “Besides,” she added between her laughter over the situation, “is this not normal for you and Frisk?”

Sans snorted. Frisk was hanging on his back trying to look at the notebook he was attempting to write in. Every now and then they would questioningly call Sans’s name and point at the book. Sans wasn’t sure if they just wanted attention or if they were honestly curious about what he was writing. Or if they had any idea what a pencil and notebook were. “‘s not quite like this.” Sans told her. He was two seconds away from grabbing the child and tickling them into submission.

“Close enough.” Toriel teased. She paused with an expectant air which caused Sans to wait to see what she would say, but she didn’t continue. Her eyes darted from Sans to the child as she sighed, deciding not to voice what she had to say. Sans would have to ask her about it when he didn’t have a pet following him.

“alright i give. what is it, kiddo?” Sans finally asked, turning his head to look at Frisk. They just stared at him and didn’t respond. They seemed contented with his attention. Sans was starting to get reminded of his cat. He turned back to Toriel seeing as Frisk wasn’t about to talk more. “hope you don’t mind me inviting the gang over. once alphys heard that frisk disappeared to another universe again, she told undyne.”

Toriel stood up and smoothed down her shirt. “It seems inevitable that my house will be full again soon. Asgore will be arriving as well.”

“it really will be a full house then.” Sans wondered if that would be too overwhelming for Frisk. The kid had started calling his name again.

“Most certainly. Will you be able to work with all of the distractions?”

“dunno. let’see if ticklin’ll calm them down.” Sans grabbed the child and threw them onto the couch, aiming for their ribs to tickle. Frisk gasped once, but other than that didn’t react to the tickles. Sans paused at their blank look. Okay that wasn’t what he had been expecting. He tried for their feet instead. They still didn’t react, just watching him curiously. Their toes did curl some when he grabbed them. The neck was last, but other than ducking their head to block the attack, they didn’t seem to care. Sans released them.

“Well then.” Toriel rubbed her chin some. “What a curious child.”

Sans had to admit that he was disappointed. He leaned back and relaxed against the large couch. “definitely. wish they could talk more so we could find out about their world.”

Frisk rolled back onto their hands and knees and moved to lay their head on his lap, curling up with a yawn. Oh, maybe that’s what Frisk had wanted the whole time. How often did little kids need to nap? He glanced at the clock. It was a little past midday. The others should be arriving soon. He placed a hand on Frisk’s head and brushed their hair back out of their face.

Both Toriel and Sans allowed the child to rest by occupying their time with new jokes they had found or made up. It was difficult not waking up Frisk with their barely-muffled laughter. Especially when Toriel did that little involuntary snort laugh that would send Sans into stitches each time. It was only when they were both certain that Frisk was asleep did Sans switch gears to ask quietly,

“everything alright?”

Toriel blinked, needing to adjust to the sudden mood change, before she sighed again. She didn't bother to hide the worry that made Sans's soul tighten to see. It reminded him of darker days. “When I was bathing them last night,” she started slowly, “there were . . . marks on their right arm.” She nodded to the kid. “They look like . . . track marks.”

Sans frowned. Why would a kid use drugs? Unless the kid wasn't taking them willingly. Sans carefully pushed up the cuff of Frisk's sleeve until he found the marks Toriel had been referring to. He blanched a little at the sight. It was possible that those were track marks considering they were most certainly made by a needle, but Sans had a worse idea. The silence, the fear of new people, and the close attachment could all be explained away as just behaviors of a young child, but combined with the marks and the way the human had gone completely unresisting to his tickling -not even reacting even in places most children their age would- held some darker undertones. Sans knew what experimentation looked like on a human. He wished that he didn't.

“Sans?” Toriel called softly, pulling him from his thoughts.

Sans smiled at her, hiding most of his worry and allowing only the right amount through. “maybe they got their shots recently.”

Toriel was unamused. “Those are old wounds.”

“maybe they scar easily.”

“Sans.”

Sans closed his eyes and pet Frisk's hair a little more tenderly as he shifted their sleeve down again. “. . . let's not consider an alternative.” He told her. The older monster was silent for a long time. Sans would possibly tell her his honest thoughts later . . . but perhaps not. She seemed to sense this.

“I will go start lunch so we all have something to eat when they awaken.” Toriel said finally, gazing at Frisk with soft eyes.

Sans gave a short wave of agreement. “i’ll be here.” Maybe now he could get some thinking done in peace.

* * *

The first day Frisk was with the criminal skeleton brothers, they were forced to stay inside with Sans while Papyrus went to “his stand”. Frisk didn’t get the chance to ask Papyrus what his job was. Frisk wasn’t even sure if Papyrus knew that Frisk could talk. He’d hinted that “Little Pup” could speak, but neither brother left room in their conversations for Frisk to speak at all. The other Frisk must also be the silent type.

Sans ignored them for the most part in the beginning. Not long after Papyrus had left he had ordered Frisk to stay in this area. Frisk didn’t know this world or the area around here, but it seemed violent so they were willing to listen. Sans left not long after that. Frisk didn’t know how long they would be alone. They would need to entertain themselves, it seemed. It was lonely, but at least Sans leaving them alone implied that he trusted them a bit more. Which was nice. Frisk took what they could get.

The living area of the brothers wasn’t too large. It was a bit bigger than Frisk’s Papyrus and Sans’s house, but it didn’t have a second floor. They still had that really strange picture of a bone hanging up in their house. There was a bathroom in the back across from what looked to be a storage area. When Frisk had snooped some, they discovered guns and decided to quickly close the crates and move to a different part of the living area. There was a kitchen and a table with chairs. The kitchen looked pretty clean, which Frisk expected of Papyrus. There really wasn’t a bed anywhere, but there was a toy chest and a radio and a couch in the “living room” area. Frisk looked through the toys. They seemed to be for various ages. Frisk couldn’t get an accurate guess on Little Pup’s age when half of these toys seemed to be for toddlers. When they wandered over to one of the doors, they found a short hallway which led to what appeared to be the warehouse that Frisk had appeared in. They went back into the living area.

With their exploring done Frisk had nothing to do. They wandered back over to the couch and laid down on it to stare at the ceiling. It wasn’t often that they had absolutely nothing to do. Back in Ebott Frisk was constantly kept busy. Either they had duties to do, chores, or they had hobbies and friends. Here Frisk was reduced to nothing. They supposed that they could practice their magic.

They sat up and summoned their Soul. There was luckily plenty of room to practice their magic. They could also do a couple of exercises like Papyrus and Undyne demanded Frisk keep up with so they could stay in shape. That seemed like it would take up a good while. Frisk had plenty of time to think, though, while they proceeded to go through their rounds.

They missed their Sans. It had been nice cuddling with this one, but there was a very distinct gap between Frisk and this Sans. It was looming like a canyon that Frisk was certain they wouldn’t be able to cross any time soon. Frisk wanted to help this Sans with whatever problems he had, but it probably wasn’t their place. Plus he most likely wouldn’t appreciate it.

Would the Frisk of this world be able to help him? Did Papyrus have any idea that his brother was haunted by something? Frisk suspected that once again it had to do with Gaster. Frisk wasn’t so sure they wanted to get involved with any more Gasters.

Well maybe Frisk wasn’t needed to help Sans. Maybe it was something that could be solved by itself. Frisk was certainly curious though. They wondered how much they would be able to question Sans. He had scolded them for being too free with their answers, but they had nothing to hide. It was interesting how he wasn’t a scientist in this world. Frisk had so many questions. They hoped that Sans would return soon.

They were exhausted both physically and magically by the time Sans returned home. They grabbed a glass of water and collapsed onto the floor to drink it, panting. They hadn’t even heard Sans return home before he was standing over them carrying a plate of hot cats. Frisk perked up at the sight of him, sitting up with a heavy exhale. Maybe they had done too much today considering all of the running yesterday. They were still sore from all of that. Frisk wasn’t sure what time it was. Their phone said it was approaching evening, but their phone may have been incorrect. They greeted Sans.

“somehow i was expectin’ you to have gone home.” Sans mused.

Frisk shrugged. They had no idea when or how they were going to return home. They had yet to tell this Sans that. They wondered if it would be better to tell him now or later.

Sans moved towards the couch and hopped up on it, placing aside the plate of hot cats. Frisk’s stomach growled loudly to remind them that they hadn’t eaten anything significant since the bisicle they’d had earlier. They joined him on the couch and waited. Sans held out the hot cat towards Frisk’s mouth seemingly out of habit, surprising the human. He looked like he was just realizing what he was doing, but he didn’t manage to pull back before Frisk was taking a bite out of the offered food. Sans watched them.

“. . . good?” He asked.

Frisk nodded, glad to have some real food in their stomach. Sans held out a different hot cat for them, but Frisk refused to take it, a playful look developing on their face. The skeleton had been so fun to tease last time, they couldn’t resist doing it again.

“You won’t feed me?” They asked.

“you can feed yourself.” Sans had a shrewd look about him. He had quickly picked up on Frisk's game. Frisk had to push more.

“I can’t.”

“it’s not good to lie, kid.”

“But I want _yours_. It tastes better from you.” They murmured.

Sans’s eyes narrowed. Frisk internally cheered knowing they had flustered him a bit. His eyes sparkled more as an idea developed. “you want it?” Sans smirked deviously. “beg for it then, pup.”

Frisk blushed, now flustered themselves as they imagined themselves at his feet begging for his ‘cat. The collar was completely unnecessary for their mind to add. They weren’t sure they wanted to show that kind of side to this Sans. They shook their head, face burning. Sans chuckled, clearly reveling in winning the round. Frisk vowed to win the next one. He held the hot cat out to Frisk again, who took another bite from it. They still wondered why Sans automatically tried to feed them. They chewed on the thought.

“Do you feed Little Pup?” They asked as the finished the last of the ‘cat.

“they usually feed themselves, but they like to be fed.” Sans responded, grabbing another ‘cat for himself. “you never answered me.” Frisk tilted their head in confusion. “when are you leavin’?”

That hadn’t been a question earlier. Frisk shrugged in response. Sans waited. Frisk picked at some of the breading on their ‘cat. “I’m not certain . . . how I got here. Last time it happened . . . it had been the other universe’s fault. An accident.” They looked at Sans. “But you don’t do science, right?”

Sans face turned bitterly rueful. “no. that’s more my brother’s thing.”

Frisk frowned. “Papyrus?” They couldn’t imagine Papyrus as a scientist.

“no.” Sans didn’t continue. Frisk chewed their hot cat in thought before they understood.

“Oh.”

“figured it out then?” Frisk didn’t respond. Sans scoffed. “‘m guessin’ gaster ain’t related to your sans?” Frisk shrugged, honestly unsure. Sans never really went into details about the nature of his relationship with Gaster. Frisk never asked.

“In the other universe I’ve been to . . .” Frisk told him, “Gaster was Sans’s colleague. Probably boss. I think he had a crush on him.”

The disgust on Sans’s face would’ve made Frisk laugh if they didn’t know it would probably anger him. They shrugged to tell him they didn’t understand it either.

Frisk thought it would be prudent to change the topic. “Are you both criminals?”

Sans pulled out a cigar from his pocket along with a lighter. He flicked the flame on and lit the cigar, inhaling deeply. Frisk made a face. He turned to blow the smoke away from their face before saying, “yeah. this city is full of mobs.”

Frisk hadn’t considered mobs. “Others?” They asked carefully.

Sans looked like he didn’t particularly care to explain. “there’s a lot of us. but for our group it’s just me and pap now.”

“Old Boss?”

“you’d know her as toriel.”

Frisk stared at him with wide eyes. They couldn’t imagine that at all. Their mouth opened and closed a couple of times, but they needed a few moments to try to think of Toriel as a criminal.

Sans laughed. “that shocking?” Frisk nodded.

“Do you . . . kill people?” They asked quietly.

“nah. just steal some stuff.” Sans stood up and grabbed his dish to drop into the sink before motioning to Frisk. “let’s go. papyrus is supposed to meet us at grillby’s. he can bring you home.”

Frisk hurried to his side as he led them out through the warehouse. “where will you go?” They asked.

“i got a gig tonight.”

Frisk perked up. “Comedy?”

Sans raised an amused eyebrow bone. “no.” He snuffed out his cigar on the ground.

It was a long walk to Grillby’s. Frisk thought it looked much nicer than the Grillby’s they were used to. The inside had a bit of a rustic feel, almost a step above the grease bar they were used to eating at. There was still plenty of grease in the air, but it was balanced out with the smells of perfume and cologne. Sans led Frisk down a set of stairs half-hidden off to the side of the bar with a nod towards Grillbz himself. The monster nodded back.

Downstairs was a completely different world. There was a bar down there as well that seemed to be run by this universe’s version of Flareez, Grillbz’s daughter. This lower room appeared to be more of a lounge than just a typical bar. There were comfy red seats everywhere and intimate candles. There was a small stage where a piano sat with a pianist playing some soft background jazz. Frisk felt like they could really relax here.

Papyrus was already there, tucked into one of the booths in the corner. It had a privacy lace curtain, but it wasn’t in use. Papyrus had a glass of some dessert drink in his hand. He made an annoyed noise as Frisk and Sans slid into the booth. “THERE YOU ARE!” Papyrus scolded. “YOU WERE SUPPOSED TO BE HERE TEN MINUTES AGO!” His voice was lower, but still loud. It was a testiment for how often the brothers were here that they were only given a small number of dirty looks.

“had a bit of a snack break and i needed to walk the pup.” Sans made up. Frisk eyed Papyrus’s drink curiously. It looked like it would taste good.

“WELL YOU’RE UP NEXT. YOU’D BETTER GO!” Papyrus waved his hand. Sans gave a lazy salute before climbing out of the booth and walking back towards Flareez. Papyrus huffed next to Frisk. “WELL AT LEAST HE ACTUALLY TOOK CARE OF YOU. HE WAS WORRIED ABOUT LEAVING YOU ALONE. I TOLD HIM THAT YOU WOULD BE FINE, BIG LITTLE PUP. AFTER ALL, LITTLE PUP COULD TAKE CARE OF THEMSELVES AND THEY’RE JUST A KID!”

Frisk looked at Papyrus in surprise, but it faded quickly. They supposed that they should really stop underestimating Papyrus so much. “Sorry.” Frisk felt the need to apologize.

Papyrus just grinned. “LITTLE PUP IS OKAY, RIGHT? THAT’S ALL I NEED TO KNOW, REALLY.” Frisk nodded. They were positive Little Pup was happy and healthy where they were. Papyrus was pleased. “GOOD! AND YOU?” Frisk nodded again. The skeleton didn’t seem upset that his brother hadn’t told him the truth, but who was Frisk to point that out? Maybe these brothers had a different relationship.

Frisk pointed at Papyrus’s drink in question. He laughed and patted Frisk’s head. “SORRY LITTLE BIG PUP. OLD BOSS WOULD GET ANGRY AT US AGAIN IF SHE FOUND OUT WE LET YOU DRINK.”

“Especially since she is right here.” Frisk straightened in surprise at the sight of Toriel as she approached the booth. There was a sternness to her face that Frisk wasn’t used to seeing outside of the Underground, but her face relaxed slightly at the sight of them. She stared back at Frisk with her own surprise. “Oh my, you were not kidding when you said the child was bigger.” She shot Papyrus a serious look. “What happened?”

Papyrus flinched at Toriel’s “serious” voice. Frisk wondered what Toriel was like as a mob boss. “W-WELL YOU SEE, MA’AM . . .”

“It’s hard to _kid_ about me as an adult.” Frisk attempted to diffuse the situation. Toriel blinked at Frisk. It took a moment for the bad joke to process, which made Papyrus groan as Toriel let out a bark of a laugh. She covered her mouth quickly, but Frisk was already grinning.

“Jokes, young one?” Toriel asked as she maneuvered into the booth. It was a bit of a tight fit, but they managed. “Who are you, dear?”

“Little Pup.” Frisk admitted. “But a different one. It’s . . . a long story.”

Toriel folded her hands together and placed them on the table, her back straight. Frisk recognized their mother’s queenly mode. Papyrus was quick to close the lace blackout privacy curtain. They could still see out, but nobody could see in. Frisk could sense some magic on it as well. Was it to block noise?

“Explain.” The old boss commanded, and Frisk knew they had no choice. They summarized the accidental switching of universes and the fact that alternate universes were a thing. They explained that, no, they didn’t know how they got there. But they also admitted that their Sans would probably be working on trying to get them back. Frisk already knew about his ideas for a universe-hopping device. They wondered if Sans was already working on it.

Toriel seemed suspicious after Frisk finished. “It all seems very unlikely.” She finally said.

“IT SOUNDS AMAZING!” Papyrus denied. “BUT ALSO VERY FAKE. ARE YOU SURE, LITTLE BIG PUP?”

Frisk nodded. The proof was their existence, after all.

“The child is well, then?” Toriel asked. Frisk could hear the care in her voice that she tried to hide. Too bad for Toriel that Frisk knew their parents very well. They nodded. She sighed, relief escaping her. “At least someone is working to fix this then.”

“Does Little Pup live with you all the time?” Frisk asked Papyrus.

“YES.” Papyrus told them cheerfully. Frisk tilted their head, a little confused. “DO YOU NOT?”

Frisk rocked their hand back and forth. “I live with my mom.”

“You have a mother?” Toriel asked, surprised. Frisk pointed at Toriel. She reared back, startled. “Me?” Frisk nodded. Toriel looked to the side, troubled but obviously pleased. Frisk wanted to ask more about their lives, but the lights around the room dropped down to lower levels and the stage lit up. There on it sat Sans, dressed in an even nicer outfit than earlier with a trilby hat and a deep blue shirt that sent Frisk’s heart fluttering. He had his trombone out and ready. Together with a small jazz band, he began to play. Frisk could only gape. Their Sans only knew how to play a few basic things on his trombone. Frisk was astounded. This world was so interesting.

* * *

“HOLY CRAP.” Undyne cried out the moment she laid eyes on the small Frisk. “LOOK HOW TINY THAT KID IS!”

“Undyne, please.” Asgore placed a hand on the woman’s shoulder before she could charge at Frisk and scare the poor kid.

“H-Hi Toriel. Hi Sans.” Alphys greeted, adjusting her glasses as she slipped past the taller monsters to get a look at the small human. Frisk was stiff next to Sans, gripping their arm tightly. It must be a nervous habit, Sans realized. Or maybe it was that the other universe's Alphys . . . but no, Frisk wasn’t really looking at any of the new monsters, but they did glance every now and again. They didn't seem especially scared of one person, but rather unnerved by the sheer amount of people.

“Careful not to startle the young one.” Toriel warned from where she stood in the entrance to the kitchen. The scent of fresh pasta salad and a baking sheet of cookies filled the air. Frisk had just woken up not too long ago. Sans had set aside his work to greet the others. Papyrus wouldn’t be back until much later. “I do not believe they are used to so many people.”

Frisk shuffled anxiously in their place.

Undyne took the hint, but still approached Frisk. She put her hands on her hips, her grin wide with sharp teeth. Frisk stared, going slightly pale at the sight. “Well! Look at you, squirt! You know me?” Frisk didn’t respond. “Don’t be shy!!”

“the kid talks even less than ours.” Sans explained. “don’t expect them to say anything.”

“How long ago did Frisk switch places with this child?” Asgore asked, lowering himself to sit on the floor. Frisk looked between him and Undyne. Asgore smiled kindly. They ducked their head and cautiously inched closer to Sans. Sans pitied them a bit. They were very small compared to everyone else in the room.

“little less than twenty-four hours.” Sans patted Frisk’s hair to comfort them.

“W-Well Frisk was gone for a couple of days last time.” Alphys pointed out. “Maybe they’ll return on their own?”

“Hey Tori! Let me help ya out!” Undyne called as she ran into the kitchen to help set the table. Frisk relaxed a little after that.

“But recall last time the other Sans helped to return Frisk.” Asgore denied.

“Oh right.” Alphys scratched her chin.

“which is why we should get started, al.” Sans told her before he tapped Frisk. “that’s alphys and asgore. and the one with the sharp teeth is undyne.” Frisk didn’t react.

“Nice to meet you, little one.” Asgore nodded.

“Yeah, same!” Alphys agreed. Toriel and Undyne soon brought out the dishes and everyone gathered at the table. Sans and Toriel both kept an eye on Frisk to see their reaction to everything. He could see they were still nervous, but they were adjusting fairly quickly as they watched how friendly everyone was with each other. They ate their food without comment, but whenever they looked next to them at Sans, Sans fed them some of his food. It seemed to cheer them up.

Undyne snorted. “What’s that? Hitting on your lover so soon?”

“nah. just feedin’ the puppy.”

“It is this Frisk’s nickname.” Toriel explained.

“Puppy?” Asgore asked.

“Little Pup.” Alphys said, “Right?”

“yeah.” Sans confirmed. He brought an onion to Frisk’s mouth. They eagerly took a bite, but made a bit of a face. Sans found that they reacted quite expressively to eating. He wanted to feed them all sorts of things. It would be so easy to feed them things that would not taste very good.

When lunch was finished, the others retreated from the table to the living room to see if Frisk would either play or talk with them. The kid clearly wasn’t super comfortable. Sans made sure that Frisk was able to see him as he stood with Alphys and showed her his calculations. She hummed, impressed, but was quick to start correcting him. They needed to get started on this soon considering they didn’t know how long it would take to build the machine. Sans didn’t doubt that this Frisk was being missed by their friends and family, so Sans would need to make sure to return them as soon as he could. Besides, it was becoming annoying having his Frisk stolen from him so much. Why couldn’t the kid stay in this timeline, this moment, this dimension, and this freaking universe?

* * *

The next two days were much the same as the first, only this time when Papyrus and Sans went on one of their jobs they didn’t take Frisk. They did, however, take the crates full of guns with them. If they had to guess, Frisk would say they were either selling them illegally or smuggling them for a “client”. Frisk was rather glad that they had stayed home. They ate with the brothers and slept on the couch with them. Papyrus occasionally tried to teach Frisk tricks, and was delighted when Frisk went along with a couple of them. It seemed that the skeleton still believed they were a dog, even if it wasn’t the dog he was used to.

Sans didn’t talk to Frisk anymore about their lives or about Little Pup, but Papyrus was more willing to talk about it. They followed him to his spaghetti stand and sat with him while he was on the job. He gladly chatted about most anything, including the politics of the city. Apparently the city was run by multiple mobs, all of which were on fairly friendly terms with each other due to the negotiating of Asgore and Toriel. Frisk learned that once again Toriel and Asgore were separated in this world, although Papyrus couldn’t (or wouldn’t) explain why. Frisk didn’t ask for more details, but they had their suspicions. Toriel had had that darkness in her eyes that Frisk recognized.

“THE SPAGHETTI STAND DOESN’T MAKE MUCH MONEY, BUT IT’S STILL FUN AND USEFUL.” Papyrus explained as he sold another bowl. Frisk wasn’t sure as to why monsters would randomly buy spaghetti from a stand in the middle of the city, but Frisk also supposed they had bought stranger things from stranger stands.

It was starting to get late and Papyrus began to pack up his stand. Frisk moved to help him, picking up the plastic bowls and stacking them. Papyrus had actually managed to sell quite a bit, Frisk noted as they counted the bowls. Maybe his food was popular? Frisk had yet to actually taste this Papyrus’s cooking. Was it really good enough to sell?

“OH! HELLO, UNDYNE!” Frisk lifted their head to see the approaching figure of this world’s Undyne. She was dressed nicely as well in a pressed shirt and suit. She didn’t wear a tie, though. Her hair wasn’t shaved on the side, but it was still pulled back into a neat ponytail. Frisk swallowed. Wow, she was attractive. Frisk hoped that this world’s Alphys was all over that. They wondered if they would be able to sneak a picture. She was almost as attractive as the woman had been on her wedding day. Were mob members required to look as dashing as possible? “YOU JUST MISSED MY LAST BATCH OF SPECIAL PAPYRUS SPAGHETTI!”

Undyne scratched the back of her head, clearly uncomfortable. She gave him an awkward smile anyway. “. . . oh . . . yeah. Damn. Maybe next time?” She didn’t sound very enthusiastic. Frisk wondered what was wrong with her.

“LET ME KNOW BEFOREHAND AND I’LL MAKE SURE TO LEAVE YOU A PLATE! NYEH HEH!” Papyrus chuckled cheerfully, finishing gathering up his supplies. He placed them down next to the bag of plates Frisk had packed. He didn’t see the way Undyne’s smile fell, watching him.

Her eyes darted to Frisk and back to the skeleton. “Who’s this? Business partner?”

“OH! THIS IS MY FRIEND! THEY WERE JUST HELPING ME OUT TODAY!” Papyrus informed her. Frisk stayed quiet, noticing that he hadn’t called them by either their name or nickname. They gave a quick wave to Undyne. She seemed to be resisting a bit of a sneer, more out of her own clearly problematic feelings rather than because she had a problem with Frisk, and gave a nod in greeting back.

Undyne looked down for a moment, considering something, before she looked up again. “. . . Pap.” She called. He hummed. “Can I talk to you alone?” She shot a pointed look at Frisk. Frisk looked at Papyrus.

“CAN WE TALK HERE? I JUST NEED TO FINISH CLOSING! DON’T WORRY ABOUT MY FRIEND. THEY WON’T SAY ANYTHING.” Undyne still didn’t look pleased. Papyrus scooped up his “closed sign and moved to hang it up as the woman gave in and began to talk,

“Where did little pup come from?” Frisk subtly inched so their face was more hidden behind the stand’s sign. Undyne hadn’t seemed to have made the connection of Frisk’s looks to Little Pup, but they didn’t want to risk anything. They also wanted to seem more unassuming to Undyne. She didn’t give off the same fierce aura as Frisk’s Undyne did, but she still had that same blood knight feeling to her.

“WE FOUND THEM AND BROUGHT THEM HOME!” Papyrus explained.

“Did they do anything?”

“WHAT DO YOU MEAN?”

Undyne hesitated, then asked quietly, “ . . . maybe . . . turn violent?” Papyrus flinched, his smile freezing as he looked at Undyne. Frisk frowned. The skeleton recovered quickly.

“A-AH . . . U-U-UH . . .” He panicked, fidgeting and scrambling with something to distract himself. Papyrus could be such a terrible liar, but Frisk couldn’t believe he was failing at a time like this. Undyne’s eyes narrowed at his little anxious dance. “WOWIE! LOOK AT THE TIME! THE GREAT PAPYRUS SHOULD BE HOME AT THIS HOUR!” Papyrus grabbed his pots and stuff for the spaghetti and linked his arm with Frisk’s hurrying them. “COME ON, FRIEND! S-SEE YOU AGAIN, UNDYNE!” He tried to abscond.

“PAPYRUS!” Undyne yelled, making the skeleton flinch and freeze in place. Frisk felt nervous just being next to the sweaty skeleton. What were they even talking about? Neither brother had mentioned Little Pup being anything but a cute kid. Frisk had a sinking feeling about this. Papyrus reluctantly turned to his friend. Undyne looked uncomfortable and almost worried. She rubbed her shoulder, avoiding the skeleton’s gaze. “Listen.” Her voice was soft but deadly serious. “I’m warning you as a friend.” Her grin was harsh, more of a threat than anything. The sclera of her exposed eye blackened, making Frisk shiver. They hadn’t known that Undyne could look like that when she wasn’t half dead and filled with determination. **“GET. RID. OF. THEM.”**

Frisk looked at Papyrus, hiding the fear they felt. Old memories of their sins crept down their back. Papyrus didn’t respond for a long moment. Undyne’s face returned to normal, although she still glared seriously at the skeleton. “THANK YOU, UNDYNE.” Papyrus finally said, and he smiled apologetically. “BUT I CAN’T.”

Undyne lifted her head, clearly horrifically surprised at the rejection, before she scowled and turned away. Papyrus didn’t stay to watch her depart, already turning himself to head home. Frisk looked between the two and stared after Undyne. They could just make out the woman muttering, “You stupid bonehead.” before she had gotten too far. Her voice had been laced with frustration and just a hint of sadness. Frisk had a feeling of foreboding before they turned and hurried after Papyrus with the rest of the stand’s supplies.

* * *

It was tough trying to get any kind of work done while Lil Pup needed to be attached to either Papyrus or Sans. Not literally, of course, but the child didn’t seem comfortable being separated from both at the same time, which meant that one of the brothers was necessary to take care of them at every point in the day. And Sans didn’t always have that kind of time, although by default Little Pup was hoisted off onto him. Papyrus happily cared for the child when he was around, but Papyrus had a day job that often called him away. So Sans had to bring Little Pup with him to Alphys’s laboratory and needed items to distract them so that they didn’t touch anything bad.

Frisk, however, didn’t act up whatsoever. Sometimes they wandered to go look at a machine or some books, but for the most part they were good. They were actually almost subdued around all of the equipment. Sans wasn’t sure if that was because they knew better than to play with anything, if it was because nothing in the lab could hold their interest over the few toys and books that Toriel had granted the child from Frisk’s old stuff, or if it was because Little Pup, for whatever reason, disliked laboratories. It gave more proof towards that dark idea Sans had thought of relating to the kid's scars. Sans preferred to think of it as one of the first two, rather than the last one.

It was easier than expected to get the prototype well on its way to being built. Alphys had plenty of money from the various machines she had built and patented, and she gladly put money towards this kind of technology. It was a challenge for both of them that stimulated Sans mentally. He had forgotten the thrill of working on something so exciting. This time he wouldn’t be as foolish though. This time he needed it to get his Frisk back. He would be extremely careful with his calculations. He hadn’t slept in the past three days.

“YOU SHOULD SLEEP, BROTHER.” Papyrus nudged his brother, who had been dozing off. Sans jolted awake and rubbed his eye sockets. He hadn’t even really napped.

“maybe tonight.” He yawned. He looked around for Little Pup and found them playing with their ball not too far away. Papyrus had suggested a break was due and had dragged both of them to the park. The kid seemed to appreciate the fresh air and a chance to stretch their legs. Up until a few moments ago Papyrus had been playing with them while Sans had rested, but now the brothers sat together in the shade of the trees.

“HAVE YOU EVEN NAPPED?”

Sans waved off his brother’s worries. “‘m fine, bro. how’s the babysittin’?”

“I LIKE IT! LITTLE PUP IS EXTREMELY WELL-BEHAVED.” Little Pup turned at the sound of their name. Papyrus waved at them. They gave a short wave back before they kicked their ball into the air. Sans wrapped magic around the ball so it flew a little closer to them and away from the street. Little Pup went after it, arms in the air to try to catch it. Sans yawned again, allowing the ball to drop. Frisk didn’t quite manage to catch it as it bounced off of their chest. They ran after it as it rolled towards the street, but startled backwards as a car passed by. They were still unsure about cars. Sans quickly got to his feet and motioned to Papyrus, pointing at the child.

“NO, LITTLE PUP! COME BACK OVER HERE!” He called, hurrying towards them. There was a car approaching fast. Frisk glanced back at the car before looking at Papyrus. They shifted from foot to foot before they looked at the ball in the street and at the car again. Sans could see the moment they made their decision. The ball was only a couple feet away after all. Sans was already moving through the shortcut closest to him.

Frisk ran out into the street and grabbed their ball. They turned to rush back to the sidewalk, but they weren’t used to cars. They weren’t aware of how fast they moved. They stopped in the middle of the street, body freezing up as the car blared its horn. Sans reappeared before Papyrus could get there, throwing out his blue magic and latching onto their Soul before changing their gravity. Frisk made a small petrified noise as they fell sideways out of the way of the car. The car slammed on it’s brakes as the ball popped under its tires. Sans caught the human and fell backwards himself from the sudden collision, only to be caught by Papyrus. Frisk trembled in their arms as Papyrus held both his brother and the human close. The car sped off again.

“I’M CALLING THE POLICE.” Papyrus told his brother, voice shaking ever so slightly. Sans brushed Frisk’s hair out of their face, but they weren’t looking at him. Their face was pale, but completely blank like it usually was. There was only the smallest tremor in their body. Sans’s own limbs shook from the adrenaline. He nudged Papyrus until they escaped his arms while his brother reported the incident to the local dogs. They would get on it soon enough. Sans wanted to get the kid home.

“papyrus.” He shared a look with Papyrus, and both brothers stood up. Sans held the kid for a moment longer as he lowered them to their feet. “come on, pal. let’s head home. you’re alright.” Frisk looked at him, but didn’t say anything. Their grip on his hand was tight as the three of them walked quickly back to the brothers’ house. They made sure to keep Frisk between the two of them.

Inside the house, Papyrus patted Frisk down to double check them before nodding with satisfaction. “THAT HAD BEEN SCARY. SANS, I’M GOING TO GO MAKE A QUICK MEAL TO SETTLE THE STOMACH.”

Sans nodded, still a little shaken himself. It wasn’t the first time a Frisk had nearly been hit by a car (honestly, what was _with_ Frisks and being so danger-prone?) but something about this Frisk being so young and in danger had set him on edge. He wasn’t used to these types of scares anymore. It wasn’t a pleasant feeling. Frisk had already recovered enough to wander over to the box of bones Papyrus had brought out earlier to show the kid. Sans sighed and ran a hand over his face. He was exhausted. Maybe Papyrus was right about trying to sleep.

Sans felt the spike of LV before he saw the movement of the kid. They darted in close to him and swiped at him with one of the smaller bones from the bone pile. Sans’s soul jumped as he instinctively dodged and lashed out with blue magic, slamming the human against the wall. He was back in the judgement hall again, Frisk standing before him with a carefully blank face. A small dark smile quirked their lips, just barely showing their teeth. It appeared to be sadistic delight. He grinned back to hide his fury and hatred. They moved again swiping at him a second time. Sans dodged.

He couldn’t wait to kill them, but he knew they would come back. He had already killed them multiple times, he knew. He had seen it in the look on their face. The fury that greeted him when they’d approached him for battle was almost hilarious. Sans just wished that he was given the chance to celebrate his victory over the hellspawn before they somehow started over again.

He lashed out with his bones, hearing something he didn’t recognize shatter. It barely registered as odd before the kid had tackled him. Their Soul was present and bright red in his face. Sans wished that he could just grab and crush the thing, but he needed to kill the body before he could break the Soul. The child was insanely strong. It was difficult for Sans to hold them off as they reached towards his chest with one hand and attempted to smash his skull in with the knife in their other hand.

Sans grinned victoriously, sweating. “my win, kid.” He summoned his bones on either side of him, fully prepared to skewer the open human in front of them. The human didn’t even react to what he had to say. One final mock. He would kill them over and over if he had to as long as he could get them to quit. This time he would succeed. The bones erupted from the ground−

“SANS, NO!!” The kid was flung back from Sans. The skeleton sat up swiftly, the illusion of the judgement hall breaking to expose Papyrus with the human struggling in his arms. Papyrus’s eyes were wide as he looked fearfully at Sans and then at the human. How was he here? Papyrus was dead. He knew Papyrus was dead. Sans had seen his brother’s dust. Papyrus was dead.

But Papyrus was right there. He was there and holding the child.

Papyrus was dead, his dust blowing in the breeze created by the cascading waterfall.

Papyrus was shushing the human, holding them close even as they bit and clawed at him like an animal. His voice was a familiar balm on Sans’s nerves.

Papyrus was dead. He was dead. He was . . . he was . . .?

“pap?” Sans called quietly. The human’s struggles were weakening, but they were still crying out in anger and determination. They couldn’t maneuver the large weapon in their hands in a way that could hurt Papyrus properly. Papyrus rubbed their back and continued to murmur soothing words. Sans wanted to throw the child across the room. He wanted them away from Papyrus. They would hurt him again. They _had_ hurt him. Sans could sense his brother’s health had depleted a bit.

“HERE, SANS. HAND ME YOUR JACKET PLEASE.” Papyrus curled up so the child was pressed to his chest, but allowed him to extend an arm without letting them escape. They bit down on his shoulder again, causing him to wince.

“p-pap, bro, get away from them. they’re a murderer!” Sans reached towards them, summoning his magic again, but Papyrus grabbed his hand and held it. His eye sockets were soft as he smiled gently at Sans.

“THEY’RE HAVING A NIGHTMARE. THEY WON’T HURT ANYONE. YOUR JACKET.” Sans moved automatically, the words “they’re having a nightmare” repeating in his head. What did one do during a nightmare? Frisk wore his jacket. The jacket would calm them down. He handed it over. Papyrus wrapped the jacket around the human. “HERE YOU GO, LITTLE PUP. THIS HELPS OUR FRISK WHEN THEY HAVE NIGHTMARES!”

They would hurt him. They were going to hurt Papyrus. Their struggles tapered off before their body went limp in his brother’s arms, the bone in their hand dropping from their slack grip. “papyrus−!” Sans tried to warn again.

“IT’S OKAY, SANS. ARE YOU ALRIGHT? IT WAS JUST AN ACCIDENT. WE’RE ALL SAFE.”

Sans was shaking. He couldn’t stop shaking. He needed to get it together. He needed to get that human away from Papyrus. They could be pretending. They could still hurt him. It would just take one hit. One hit and his brother would be gone again. “no. no, papyrus, you don’t get it. they _killed_ −”

“BROTHER, WE’RE SAFE.” Papyrus cut him off. “DO YOU KNOW WHERE WE ARE? WE’RE AT HOME. SEE? THERE’S THE TV! AND OUR FAVORITE BONE PICTURE! AND CAN YOU SMELL THE DINNER COOKING? YOU WERE HAVING A FLASHBACK. I SWEAR TO YOU THAT WE’RE ALL SAFE.TAKE A COUPLE OF DEEP BREATHS. SLOWLY NOW. CAN I TOUCH YOU? MAY I SEE YOUR HAND?”

Why was he talking like that? Sans tried to process it even as he reached for his brother and took his hand. He gripped Papyrus’s hand and reluctantly tore his eyes away from the human to look around the room. They really were at home. This wasn’t the home in Snowdin. He started to pick up the little differences. The scent of the mac and cheese it seemed Papyrus had chosen to make. The worn feeling of the rug beneath his hands and knees. His bleached complexion reflected back at him from the television screen. There was a broken glass on the rug.

He blinked rapidly and looked back at Papyrus. His brother gave him a reassuring smile. The child in Papyrus’s arms no longer looked like the same Frisk. They were smaller and their outfit was completely different from the striped sweater he was used to seeing in his nightmares. Adrenaline was still telling him to move, to save his brother, to kill the human, but the more rational part of his mind began to break through.

He was home. He was safe. This wasn’t his Frisk, but they wouldn’t attack anymore. He couldn’t question why they had attacked him yet. He wasn’t even sure if they did attack him. Had that been his imagination? What had triggered him? He was so confused. But Papyrus’s hand was steady in his. Sans felt like he would collapse if his stiff limbs would let him. He realized his brother was still talking to him, trying to coach him through his panic.

“DEEP BREATHS, SANS. SLOW DEEP BREATHS. CAN YOU HEAR ME?” Sans nodded shakily and placed his head in his other hand, following his brother’s directions. It was hard to breathe, but it was becoming easier. His mind wasn’t quite as muddled now. He was alright. He just needed to calm down.

“th-thanks, bro.”

“ARE YOU BACK WITH US?”

“yeah.” As much as he could be, anyway. Sans wanted to go into his bedroom and curl up on his bed. He wanted Frisk back so he could listen to their heartbeat and count their breaths, but he cringed at the very thought of them touching him. Papyrus was okay, though. His bones were familiar. He longed to be Syrus suddenly.

“DO YOU FEEL ALRIGHT? DO YOU NEED ANYTHING?” Papyrus waited patiently for Sans’s slow mind to process it all. He shook his head.

“um . . . no. no, i’m fine.” He stared at the human. “are they alright?”

Papyrus pushed the human’s fringe out of their face. They were out cold. Did Sans do that? He couldn’t remember. “THEY APPEAR TO HAVE PASSED OUT. BUT OTHER THAN THAT, I THINK THEY’RE UNINJURED. EXCEPT THEY SEEMED TO HAVE HIT THEIR HEAD. I GOT OUT HERE FAST ENOUGH TO STOP ANY INJURIES.” Papyrus carefully prodded at the human's head. There was some blood on his fingers. Sans felt sick at the sight.

So they had attacked him. Or . . . Sans had attacked them? He tried to remember what happened before his flashback had overtaken him. “that’s good.” He grinned a shaky smile. “good job, papyrus. though i gotta say . . . we're shitty babysitters.”

His brother huffed a laugh. “THANK YOU. AND YOU'RE PROBABLY RIGHT.” Papyrus released Sans’s hand and slowly stood. Sans didn’t feel like getting up quite yet. “DO YOU NEED A MOMENT? I’LL TAKE LITTLE PUP INTO THE KITCHEN WITH ME.” He grabbed some pillows from the couch.

“i’ll just . . . sit here for a bit.” Sans confessed. He wasn’t sure he could stand.

“I’LL BE RIGHT IN THE KITCHEN.” Papyrus promised before he entered the kitchen. Sans could see him from where he sat. He watched his brother as he placed the pillows onto the table and tucked the human ( _Frisk. The Little Puppy._ Fuck) into the nest. He covered them with Sans’s jacket and gave Sans another smile before he turned back to the boiling water on the stove. It was hissing loudly as it boiled over.

Hot Cat cautiously wandered out from whatever hiding place she'd been in and rubbed up against Sans while purring. He ignored her knowing that she would just attack his hand if he tried to pet her, but he found some comfort in her presence. Sans covered his face with his hands and tried to breathe. That had been a bad one.

* * *

Frisk didn’t ask either of the brothers about what Undyne had talked about. They were curious, of course, but Papyrus had asked them not to mention it while they were both walking home. There had been some resignation in his voice despite his usual pep.

_“BIG LITTLE PUP. PLEASE DON’T MENTION WHAT HAPPENED EARLIER TO SANS.” Frisk looked at Papyrus in confusion. He smiled that same apologetic grin he had given Undyne. “LET’S KEEP IT A SECRET BETWEEN US, OKAY?” Frisk nodded without a word. They wouldn’t say anything._

They couldn’t bring up there being anything wrong with Little Pup without Sans being suspicious of where Frisk had gotten that information. And he finally seemed to be somewhat relaxed around the human, so they would rather not upset him again. They would have to content themselves to not knowing. However, that left Frisk with plenty of time for speculation considering there wasn’t much else to do at the warehouse. Would their Sans be alright? Things wouldn’t be good if a violent Frisk attacked him. Frisk itched to get home, already having a feeling of something being wrong. They hoped that they were just worrying about nothing. Why would a Frisk be violent? Especially violent enough that a mobster version of Undyne would warn Papyrus?

What if it wasn’t Frisk? What if Little Pup was Chara? Yes, Sans had reacted to the name “Frisk”, but did that mean Little Pup was Frisk? Perhaps they had been named wrong? Papyrus and Sans had already told Frisk how they had met Little Pup. Sans had been the one to tell Frisk later about the dogtag that the human had been wearing with Frisk’s name on it, perhaps in hope that they'd recognized it. They hadn’t.

They had been living with the brothers for close to a week now. They hadn’t heard or seen anything from Undyne in a couple of days. Frisk was becoming homesick quickly. They missed their parents and their friends. They were calmed some by sleeping with the brothers, but it still wasn’t enough. This Sans wasn’t their Sans. He didn’t hold them as close and didn’t laugh as freely. His clothes sometimes smelled of old cigars, which Frisk wasn’t sure they liked at all. They wanted to return home, but they didn’t know when or how they would.

The brothers were becoming a bit antsy too. Frisk could tell that, at least with Sans, they had overstayed their welcome. Papyrus was just as kind as before, and even Toriel popped by sometimes to spend time with Frisk, but Frisk could tell they were just waiting for Little Pup to return. Frisk hoped to grant their wishes.

Papyrus was washing up in the kitchen as Sans and Frisk sat at the table. Frisk hadn’t been feeling very hungry due to their homesickness. They had been trying not to ask the questions spinning around in their head. Their sleeping schedule had been becoming worse and worse. They missed Sans’s jacket. They could already feel the oncoming nightmare. It would arrive soon without their security blanket. They had grown used to expecting it.

To distract themselves, they turned to Sans. He was eating ice cream, getting in that dairy needed for strong bones without drinking milk. Frisk watched him for a long moment until he finally noticed their staring. He raised a bony eyebrow. “you want a bite?”

Frisk didn’t respond for a long moment, considering it, before they nodded. They opened their mouth. Sans brought the spoon close to their lips, but snatched the spoon back right before they could close their mouth around it. He looked like he had a crafty idea.

“you want some? earn it.”

Frisk blinked, interested in the challenge. They moved to sign to him their question before they remembered that this Sans and Papyrus probably didn’t know sign language. Instead they nodded in agreement. Sans grinned.

“give me a kiss.” He commanded. “you know how to give one, right?” What kind of question was that? Of course Frisk knew how to give a kiss. There was a story behind that request, they knew.

They shifted in their chair closer to Sans, where he pointed at his cheekbone. Oh, so he just wanted a cheek kiss? Frisk had other ideas. They had revenge they needed to serve, after all. They leaned forward as if to kiss his cheek, but at the last moment kissed him square on the mouth. Sans’s eyes widened briefly before Frisk stole the ice cream from the spoon and pulled back, pleased.

Sans stared at them, processing Frisk’s total success, before he leaned forward and said in a low voice, “that wasn’t what i meant.”

Frisk shrugged. “You didn’t specify.” They pointed out. Sans gave them a bland look to let them know exactly what he thought about that.

He narrowed his eyes. “knock knock.” He asked in a lowered voice. Papyrus wouldn’t be able to hear them over the sound of the water.

Frisk perked up. “Who’s there?”

“lenna.”

“Lenna who?”

“lenna little closer and i’ll tell ya.” Frisk tilted their head, curious, and did as he asked. Sans grinned and moved quickly bringing himself almost close enough to kiss Frisk, but then stopping right before he did so. Frisk’s eyes widened. “your game isn’t difficult to play.” He breathed, sending a shiver down Frisk’s spine. He leaned back then and relaxed into his chair right as Papyrus turned around. He was clearly pleased with himself. Frisk ducked their head to cover their face as Papyrus called out a question to them about food. Frisk was suddenly ravenous.

* * *

Whatever had happened to the Little Pup, it caused them to become sick right afterwards. Their temperature had increased dramatically, and Toriel was called in to help care for the child. According to Papyrus, Little Pup had no idea what had happened, or at least didn’t seem to show it. This was all told to Sans. He stayed away from the human, coping in the best way he could by throwing himself into his work. He had finally gotten some sleep not too long after the event, eventually just crashing, but he hadn’t stayed asleep long before he was jolting awake from his own nightmares. His first response was to find Frisk, but his body physically rejected the idea. The next thought was to find Papyrus, but he would be taking care of the little human, so Sans didn’t do that either. He stayed in his room and buried his face in his legs.

Later he finally crawled out of his room and left the human to Papyrus’s care. He briefly checked on them, but they were unconscious with their fever. Sans couldn’t bring himself to approach them and instead left the house to go to Alphys’s. He wasn’t sure if they were aware of Little Pup’s outburst, but neither Alphys nor Undyne brought it up. Not long after Sans arrived, Undyne left to go visit the human herself.

Sans focused on getting at least a prototype of the machine working. If he was going to be awake, he’d rather be awake and working. Alphys no longer had the same mentality about work as she once did (now that she had a happy job and family life that didn’t stress her out to no end), but she didn’t seem to mind Sans spending exorbitant amounts of time in her lab. She only kicked him out when it got particularly late.

After the first couple of days, Little Pup recovered. Sans stood in the doorway to the kitchen watching as Papyrus sat on the couch with the human and introduced them to _A Nightmare Before Christmas_. They were still wearing Sans’s jacket. It was gigantic on them. Sans hadn’t been this close to the kid since that day. The prototype was sitting in his room now, ready to be used at any time. There was a large risk with testing the machine. He was positive it would work, but he wasn’t sure how they should try it. The quickest way would be himself. He could go alone first, but there were infinite universes Frisk could be in. He needed to take a bit of this Frisk in order to direct the machine. But first he needed to approach them.

Sans took a breath. They wouldn’t attack, he was sure. They were completely fine with Papyrus. Sans had no clue why they had attacked him, but the sooner he got them home the better. It was a risk. He approached them.

“SANS! YOU’RE JUST IN TIME FOR THE CRIME OF CAPTURING THE INNOCENT SANDY CLAWS!” Papyrus announced. Sans gave a smile. He had seen the movie countless times. He really didn’t care to see it again.

“sounds awesome, pap. but i just need to borrow the kid for a moment.” Sans motioned to Little Pup, who tilted their head silently. Sans’s body protested, but he approached the human and sat next to them. Papyrus paused the movie. “how’re you feelin’ kid?” Lil Pup didn’t respond, but they seemed fine. “lemmee see your head.” Frisk tilted their head forward, and Sans gently prodded at the back of their skull. When he had thrown them across the room, they had hit their head a bit. There was a bandage still there, but luckily the wound wasn’t bad. Sans carefully unwound the bandage. There was only a tiny bit of blood on it.

“looks like you don’t need this anymore.” Sans pointed out, rubbing the top of Frisk’s hair. Frisk stared at him for a long moment before they wrapped their arms around Sans’s torso. Sans stiffened in surprise before he looked at Papyrus. His brother just smiled, delighted. Sans hesitated briefly before he hugged the child back as they buried their face into his chest. Sans sighed. “alright. forgiven.” He told them. They were probably confused, but Sans didn’t care or explain. He patted their back and pulled away, sliding back off of the couch.

“I’M GLAD YOU BOTH MADE UP!” Papyrus told them. “HUGS FOR PAPYRUS?” Little Pup hugged him as well, but Papyrus was quick to take control of the hug. Sans huffed a laugh. “WHAT ARE YOU UP TO, BROTHER?”

“think i can finally get them home.” Sans admitted, walking back towards his bedroom. Papyrus gasped.

“SO SOON?”

“we need to get them home. i’m sure their family misses them.”

“THAT’S RIGHT. THEY’RE PROBABLY MISSING ANOTHER GREAT PAPYRUS! SANS, YOU MUST WORK QUICKLY.”

“already on it.” Sans entered his room and pushed Hot Cat out of the way. The cat refused to move, forcing Sans to slide it across the rug with his foot. It rolled along it with its default grumpy face. Sans grabbed the prototype off of his dresser. He had promised Alphys not to try it until all of them were together just in case, but he could at least see if the scanner worked. He held Frisk’s bloodied bandage up to the small scanner on the back of the watch-like device. It scanned properly, but there was no way of telling if it would work to take Sans where he needed to go unless he tried it out.

He exited the bedroom to find Little Pup standing at the bottom of the stairs gazing up at him. They smiled just a little bit to see him, which lightened the heavy feeling in Sans’s chest just a little bit. He started down the stairs and patted Frisk’s head as he passed. “shouldn’t you be watchin’ the movie?” He joked.

“Sans.” Little Pup responded, following on his heels. Papyrus was enjoying the movie by himself now. A hiss erupted from behind them both, causing them to pause and look. Even Papyrus tilted himself to see better. Hot Cat hissed again from where she stood near Little Pup, aggravated for whatever crazy reason the insane cat had decided to become angry again. Little Pup stared at the creature with wide, fearless eyes. They looked back at Sans once before pointing the cat and trying to approach it. They paused when the hissing got louder.

“LITTLE PUP, YOU SHOULD PROBABLY LEAVE THE KITTY ALONE.” Papyrus warned. “SHE BECOMES EASILY INTIMIDATED BY PEOPLE. WHY, SHE HAS KNOWN ME FOR YEARS AND IS STILL INTIMIDATED BY MY GREAT PRESENCE!”

Little Pup listened and didn’t touch the cat, but Hot Cat wasn’t done with Frisk. She tried to skulk around the human, but when Frisk turned to follow her, she growled and launched herself at them. Neither Sans or Papyrus had time to react to the speedy cat before she was already kicking herself off of Little Pup and zooming out of the room, yowling angrily. Little Pup was knocked down on their back and stared up at the ceiling blinking in shock.

Sans glanced at his brother, who was already up to check on Frisk, before he started laughing. It felt good to release some of that pressure. He wiped at his eye socket as Papyrus helped the human up and patted them down. “we warned ya, kiddo. that cat’s a mean son of a bitch.”

“SANS! WATCH YOUR LANGUAGE!” Papyrus scolded.

Sans shrugged. “they won’t repeat it. they barely talk.”

“STILL. WHAT WOULD HER MAJESTY SAY IF SHE CAUGHT FRISK CURSING AT THIS AGE?” Sans could already imagine the angry grin as she proceeded to lecture Sans. He shuddered.

“. . . good point. kid, don’t repeat what i just said.” Little Pup didn’t respond, but Sans supposed that was the best he was going to get. He turned to his brother. “supposedly this thing will work,” Sans held up the prototype, “but there’s no guarantees. i’ll probably test it myself.”

Papyrus looked worried for a moment before he nodded. “YOU’VE ALWAYS BEEN GREAT AT YOUR SCIENCE, SANS. I’M SURE IT’LL WORK GREAT!”

Sans smiled a little, happy to have his brother’s support even as his mind whispered about what had happened to Gaster and the time machine. Screaming echoed in his mind. “yeah.” Hopefully this would go better. Much better.

* * *

Frisk wondered where Sans went for so long every day. He never told them or Papyrus. He would only say “i’m headed out for a bit” and then would leave. Papyrus would just wave at him not seeming to mind that he had been essentially stuck with babysitting services. They supposed that he would have to be used to it considering how young Little Pup was. At least Frisk could practice with the older skeleton. He seemed very for training the human. Excited even.

It was while Sans was gone that Frisk decided to finally bring up the question they had been quiet about for the past couple of days. They were willing to give information if they could receive information. And they had a feeling that one of the reasons why Sans was gone so much was related to Little Pup. He wasn’t trying to build a portal machine, was he? Hopefully not.

“Papyrus.” Frisk called as they dodged past a wave of bones. They were out in the warehouse in a cleared section where the brothers occasionally practiced smaller fighting. The bones circled around to attack from behind, but Frisk applied blue magic to their exposed Soul and jumped over the attack. Training wasn’t one of Frisk’s favorite ways to spend their day, but it was better than nothing. And Papyrus, for whatever reason, was “laying low for a bit” as he had told them.

“YES?”

“What’s wrong with Little Pup?” Papyrus froze in his attack and the magic stopped, causing the bones to clatter to the ground. Frisk released the magic on their own Soul so that it returned to their chest and their vision regained color.

“ABSOLUTELY NOTHING! NYEH! OH WOWIE, IS IT TIME TO MAKE DINNER ALREADY? BIG LITTLE PUP, HOW ABOUT A WALK AND NOT TALKING ABOUT THIS ANYMORE?” Papyrus suggested nervously.

Frisk did join him, but they didn’t drop the subject. “I won’t say anything.” They offered their promise.

“IT’S NOT.” Papyrus stopped and sighed. “LITTLE PUP IS FINE. THEY REALLY ARE! THEY JUST . . . GET SCARED. AND ATTACK. SOMETIMES. WELL, ONE TIME. IT WAS SCARY, BUT IT WAS A NIGHTMARE.”

Frisk frowned a bit. Why would Undyne tell Papyrus to get rid of Little Pup if they only attacked the brothers when they were scared? They asked him.

“BECAUSE LITTLE PUP IS NOT THEMSELVES WHEN THEY ATTACK.” Papyrus smiled sadly before he perked up again. “BUT THEY’RE BETTER NOW! WE WON’T LET THEM GET HURT AGAIN!”

Frisk thought it may be best to drop the questioning then. They nodded in agreement with Papyrus. Knowing themselves, the Little Pup would be extremely happy with the brothers. They weren’t sure why the little human had attacked the brothers, but if it was just out of nightmares or fear then surely it was over now and they were all safe. Still Frisk was scared for their own Sans. What if Little Pup became scared and attacked Sans? That wouldn’t . . . Frisk was sure that wouldn’t end well.

Did Little Pup know how to RESET?

Sans didn’t return home until the next day appearing contemplative. The first thing he did was approach Frisk, who was on the couch attempting to finish knitting a scarf they had forgotten they had stored in their hammerspace. He hopped up onto the couch on the other side of the human and nudged their leg. “when’re you goin’ back?” He asked.

Frisk shrugged, not stopping in their stitches. They were almost done. They would give this to Papyrus before they returned to their world.

“thought you said this wasn’t a permanent thing.”

Frisk made a face. It wasn’t supposed to be a permanent thing.

“i don’t know how you plan to do it, but you need to get back to yours and give us back our kid.”

“SANS.” Papyrus interrupted. “THEY CAN’T HELP THAT THEY’RE HERE.”

“i know.” Sans smiled at his brother. “but i figure pressin’ the importance of their departure might be ideal.”

“whoa. no kiddin’.” Frisk blinked in confusion and looked at Sans. Why had he responded to himself? But Sans was already on his feet along with Papyrus facing the appearance of two arrivals.

“LITTLE PUP!!!” Papyrus cried and dashed forward, scooping up a child version of Frisk from beside a new Sans. They were wearing Sans’s large jacket. Sans himself (the new one) grinned broadly before he took in his surroundings. He blinked only once at the sight of himself before his gaze landed on Frisk.

“there you are, kid. been lookin’ for you.”

“Sans.” Frisk breathed and threw aside their items to hug him as well. He kissed the side of their neck once before he pulled back. “You found me.”

“took some lookin’ too. me ‘n the pup here had to pass through a couple of different universes until we got here. guess the aim on this thing isn’t great yet.” He looked at Little Pup, who was hovering between all versions of the brothers. “hey kid, don’t grow up to be scary like that other version of you.”

“How did you not switch with this Sans?” The older Frisk asked.

Sans gave them an amused look. “obviously that was one of the kinks me ‘n alphys fixed right away in the formula.”

“wow.” They were interrupted as the other Sans entered their conversation. He looked his counterpart up and down, vaguely impressed. “it’s one thing to hear about all this other universe stuff, but it’s another to experience it.”

“you’re tellin’ me. it’s the first time i’m meetin’ another version of me properly.” Sans agreed, shoving his hands into his shorts. He shared a devious look with Frisk before saying, “gotta question for ya, papyrus.”

“FOR ME? ASK AWAY, OTHER SANS!” Papyrus gave a small excited bounce on his heels, clearly amazed.

“what should a skeleton order at a restaurant?”

Papyrus frowned, thinking about it. “MILK IS ALWAYS A GOOD CHOICE, OF COURSE. BUT IF YOU MEAN FOOD . . . THEN SPAGHETTI IS ALWAYS A GREAT ANSWER.”

“nah, bro, a skeleton should order . . .” The Sans shared twin grins and both said, “ _spare ribs_.”

Papyrus gave a cry of outrage. “OH MY GOD, NO! NOW THERE’S TWO OF YOU! THIS IS THE WORST DAY OF MY LIFE! WORSE THAN OLD BOSS AND SANS DISCOVERING TERRIBLE JOKES!”

“no need to go to a restaurant,” His brother said, “just go to a cafeteria. if you have the _stomach_ for it.”

The Sanses laughed in harmony, bumping each other in quick camaraderie. Little Pup kept looking at them both and then at Frisk. They seemed hesitant to approach their older self. Frisk kneeled down and rubbed their head in greeting. They watched them curiously.

“anyway,” Frisk’s Sans said, “sorry it took so long to get here. building a universe-hopping device ain’t easy.”

“i’m sure.” The other Sans agreed and winked at his twin. “wouldn't be slackin' off on important stuff.” He watched the Frisks interacting. Frisk turned to their Sans and tsked him.

“Flirting with the children.” They teased.

Sans winked. “you know i only flirt with cute humans.”

Frisk looked at the other Sans, pulling their younger self closer. “Flirting with the children.” They repeated, fighting their smile.

“i’m sure you were plenty entertained with the other me here considerin' the last time you jumped universes.” Frisk’s Sans continued. “you little minx.”

“He _is_ attractive.” Frisk agreed, unashamed.

“WILL YOU TWO STOP?” Papyrus complained. “ALL OF THE FLIRTING SHOULD STOP.”

“should keep a wrangle on that kitten.” The other Sans said, ignoring his brother, “they like to get a little cozy with other yous.”

“in that getup? i’m not surprised.” Sans looked his counterpart up and down. The other Sans snorted.

“You should dress like him.” Frisk suggested.

“don’t have the patience or motivation.”

“I could give you motivation.”

“STOOOP! LITTLE PUP, QUICK! LET’S ESCAPE NOW WHILE WE CAN! PROTECT THE PUPPY’S EARS!” Papyrus scooped Little Pup up and rushed into the kitchen to spin the child around playfully. The two Sanses and Frisk watched the duo briefly before turning back to each other. Frisk wasn’t sure who won this round, but they had plans to continue it when they returned to their universe.

“hey kid,” Sans told them and nodded towards the duo, “go meet n’ greet with the little kid. say your hellos and goodbyes and all that.”

Frisk opened their mouth to protest, but realized they were being dismissed. They shot Sans a confused look before they proceeded to grab their nearly-complete scarf to finish before they headed over to the kitchen as well. The two Sanses turned to each other.

“need somethin’?” The counterpart of Sans asked. He mimicked Sans’s relaxed pose, shoving his own hands into his dress pants.

“yeah, listen.” He glanced over at Frisk to see them holding their younger self’s hands and crab-walking with them over to the now-scarf-wearing Papyrus. Papyrus seemed to be humming some song Sans didn’t recognize, but Little Pup clearly did. “that kid. watch out for them.”

Sans’s smile turned a little stiffer. “yeah?”

“yeah.” He didn’t say anymore.

Sans lowered his head a little, his grin still present. “yeah, i know. don’t worry about it.”

Sans considered his other self before he decided it best to drop it. “just wanted to warn ya.” He shrugged in dismissal. His counterpart didn’t respond. “anyway,” Sans motioned them all over again, “we’re gonna head back. ‘m sure you all have plenty of catchin’ up to do and this kid’s been out past their curfew for a long time.”

Frisk smiled already thinking about seeing their parents again.

“YOU’RE LEAVING ALREADY?” Papyrus asked.

“they gotta head back, papyrus.” His brother responded.

“OH . . . WELL, SAY HELLO TO MY OTHER SELF FOR ME, BIG LITTLE PUP!” Papyrus scooped Frisk up in a tight hug, which they returned when they managed to wiggle their arms around the skeleton. When he placed them down, they hugged Sans next and kissed his cheekbone.

“Be safe.” They told them.

Sans kneeled down next to Little Pup. “c’mere, kiddo.” Little Pup hugged him. “gonna need the jacket back.” Little Pup pet the fur inside of the jacket mournfully before they slid it off and handed it to him. Frisk gladly took the jacket. “kiss too?” He asked the child.

“yeah,” the other Sans grinned, “show him your trick, kid.”

Little Pup gazed at Sans for a long moment before they leaned back and hit their head against his jaw. It wasn’t hard enough to injure too badly, but it did stun the both of them. Papyrus made a sound of dismay while the other Sans just laughed.

“NO, LITTLE PUP. YOU HAVE TO USE YOUR MOUTH, REMEMBER? HERE, SANS, LET ME GIVE AN EXAMPLE!”

“nah.” Sans denied quickly, standing up while rubbing his jaw. “i’m good.” He took Frisk’s hand. “let’s head back.”

Frisk nodded and waved again to the brothers. “TAKE CARE!” Papyrus called.

“don’t do anything i wouldn’t.” Sans winked.

“That isn’t much.” Frisk shot back, amusing the skeleton. It was the last image they saw before they left that universe for the next one.

**Author's Note:**

> ~~At this point I wonder if I should just make another series for any universe-hopping fics. Because I have at least one more planned.~~
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> [Link to the original pictures!](http://nyublackneko.tumblr.com/post/145755419232/road-trip-au-x-ut-mob-au-crossover-fic-a-new)


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